Sinodrills Development

from its establishment to the present

Guizhou Sinodrills Equipment Co., LTD (hereinafter referred to as Sinodrills) is an international market-oriented enterprise dedicated to providing a comprehensive solution for rock drilling tools. Its predecessor, DVY International, was established in 2002 and was registered as Guizhou Sinodrills Equipment Co., LTD in 2006. After over two decades of development, Sinodrills has evolved into a professional rock drilling tool supplier integrating research and development, production, and sales. Sinodrills owns two production enterprises: Wuxue Zhong’e Machinery Equipment Co., Ltd. and Wuxue Xinchuan New Materials Co., Ltd., among which Wuxue Xinchuan New Materials Co., Ltd. is a national high-tech certified enterprise. Sinodrills is committed to providing a one-stop solution for rock drilling tools, with its products covering 4 series:

• Top-hammer drilling tools,

• Down-the-hole (DTH) drilling tools

• Geotechnical drilling tools

• Rotary drilling tools.

Sinodrills strictly adheres to the ISO9001 international quality management system and consistently upholds the principle of integrity in business operations. Since 2016, it has been recognized as a 3A enterprise by the internationally renowned credit rating agency Dun & Bradstreet. Sinodrills places innovation at the core of its business, continuously improving product quality to create more value for customers. By the end of 2023, Sinodrills had obtained more than 20 patents and has been increasing its R & D investment year by year.

Since its establishment, Sinodrills has been focusing on the mid-to-high-end international markets. By the end of 2023, its products had been exported to 110 countries and regions around the world, with its export volume in 2023 ranking first in China (certified by Euromonitor International in March 2024). As of August 2024, Sinodrills, as the leading brand of rock drilling tools in China, has been registered in 120 countries or regions worldwide.

Our mission: Take Chinese rock drilling tools to the world and earn global trust in Sino-quality;

Our vision: Make Sinodrills rock drilling tools a global bestseller and achieve annual sales of over 100 million US dollars.

Our Values: Customer satisfaction and repeat business are the only standards for our work.

Probable causes:

- Drilling under extremely abrasive conditions

- Overwhelming flushing volume

Suggested actions:

- Reduce flushing volume

- Slow drill rotation to create larger cuttings for more effective flushing

- Use drilling foam to assist in the removal of rock cuttings

- Regularly clean the drill holes

2. Skirt Wring Off

Probable causes:

- Misalignment due to hole deviation

- Improper feed pressure

- Steel fatigue

- Worn, broken, or mismatched threads

- Excessive rotational forces from operating with dull carbides

Suggested actions:

- Lower percussion and feed during the initial drilling (collaring)

- Use alignment tools and improve drilling practices for a straighter hole; Use bits with a drop center face design and/or a retract body

- Regularly sharpen dull carbides

- Avoid striking the external bit body

- Reduce the power of impacts

3. Split Skirt

Probable causes:

- Misalignment from hole deviation

-  Loose thread joints during drilling

- Drilling with excessively worn threads

Suggested actions:

- Use alignment tools and improve drilling practices for a straighter hole

- Use bits with a drop center face or retract body

- Change worn out components of the drill string

- Ensure thread joints are securely tightened before percussion

4. Steel Crack on Bit Face

Probable causes:

- Excessive feed force

- Use dull carbides for drilling

- Manufacturing error, inferior button hole-drilling precision

Suggested actions:

- Adjust feed force to match rock conditions

- Regularly sharpen dull carbides

- Return bit for detailed analysis

5. Carbides Pop-Out

Probable causes:

- Insufficient feed pressure

- Incorrect size match between button and button hole

- Excessive grinding of the bit body

- Drilling in very soft or extremely abrasive conditions

- Free hammering

Suggested actions:

- Increase feed pressure

- Adhere to correct carbide sharpening process to prevent excessive bit body grinding. Replace worn out bits.

- Commence full percussion only when the bit is in complete contact with rock

6. Snake Skin or Micro-Cracks in Carbide

Probable causes:

- Drilling in non-abrasive rock such as limestone, leading to micro-fractures in the carbide, and it looks like snake skin.

- Incorrect intervals of carbide grinding

- The rock leaves a shiny surface on the buttons and a fatigue in the surface of the cemented carbide, leading to button failure

Suggested actions:

- Shorten grinding intervals when drilling in non-abrasive

rock

- Sharpen carbides upon dullness or the appearance of micro-cracks, appropriating proper procedures

- Regular inspection of carbides

- Use a softer carbide grade

7. Carbide Chipped & Carbide Cracked

Probable causes:

- Overdrilling of the bit

- Drilling in non-abrasive rock causes a shiny surface on the buttons

- Improper grinding intervals

- Too hard carbide grade for the rock condition

- Button not making contact with virgin material on impact

Suggested actions:

- Reduce intervals between grinds. Regrind when wear flats reach a maximum of 1/3 of the button diameter

- Regularly inspect and grind bits to eliminate surface micro-cracks on the carbides

- Select an appropriate hardness of the carbide for drilling application

- Do not initiate percussion until the bit is in full contact with the rock

8. Carbides Crashed Down to Level of Bit Body & Carbides Crashed Inside the Bit Body

Probable causes:

- Overdrilling in non-abrasive rock such as limestone, leading to micro-fractures in the carbide, and it looks like snake skin.

- Excessive carbide protrusion due to poor grinding practices

- Incorrect grinding intervals

- Unsuitable carbide grade

Suggested actions:

- Shorten the intervals for grinding when drilling in non-abrasive rock

- Regularly inspect and grind the bits although the buttons may not appear worn, just polished, to lessen micro-cracks on the carbide surface

- Use wet grinding to avoid snake skin fatigue

- Choose suitable grade of carbide

1.  Hot Piercing-Hot Rolling Method

The hot piercing-hot rolling method is an effective way to produce hollow steel and is very common in China. The process involves several steps to process round billets into the required hexagonal and round hollow steel.

The general process is as follows:

Initially, round billets are cut according to production needs, preparing them for subsequent heating and piercing processes. A specially designed medium frequency inductor heats the round billets, providing preheating, temperature raising, and insulation, reaching the piercing temperature (1140-1200°C). Subsequently, a two-roll piercing machine performs oblique rolling piercing. The outer diameter and wall thickness of the pierced billet must meet subsequent process requirements. A three-roll tube rolling machine then processes the billet to achieve the required external and internal diameters. After diameter reduction, the billet requires forming rolling on a three-roll or six-roll mill to produce the required hollow steel. Finally, the rolled hollow steel undergoes cooling process to ensure the stability of its structure and properties.

The hot piercing-hot rolling technique uses advanced heating and piercing equipment, as well as precise control techniques, ensuring dimensional accuracy and ensuring the core holes are properly rounded. However, during the piercing and diameter reduction stages, fine spiral cracks and decarburization are easily to occur on the surface of the core hole, resulting in poor performance and stability of the manufactured rock drill rods, making them economically suitable for use in low hardness, uniformly distributed rock drilling environments.

2.  Hot Rolling with Core Method

The hot rolling with core method, originating in Europe, utilizes continuous cast billets and high manganese steel core materials.

The process is roughly as follows:

Continuous cast billets are cut according to production needs. After center drilling, an 80Mn14 core material is inserted, followed by heating in a continuous heating furnace. The heating temperature is controlled between 1050 and 1200°C. After exiting the furnace, the billet enters the rolling stage. Before rolling, high-pressure water descales the billet, removing the oxidized layer. The unit then rolls the billet into required hexagonal or round hollow steel shapes, with rolling temperatures controlled between 950 and 1180°C, and final rolling temperatures controlled between 830 and 950°C. After rolling, the rolled piece is transferred to a cooling bed for temperature and cooling control, then the core is withdrawn.

Due to the different expansion coefficients between the high manganese steel and the hollow steel billets, high manganese steel shrinks uniformly,  and is extendable by 40%-60%, the core is easily withdrawn when cooled to room temperature, resulting in a smooth core holes and good mechanical properties of the hollow steel. The hot rolling with core method produces high-quality, stable-performance hollow steel, well-suited for hard, unevenly distributed, fractured rock layers. This method is also one of the mature hollow steel production techniques currently available worldwide.

From November 26th to 29th, 2024, SINODRILLS attended BAUMA CHINA 2024 with our in-house produced self-drilling anchor tools. As the first company to publicize the production process of this products through video, we attracted a large number of domestic and foreign customers to stop for viewing and inquiries.

As China’s leading exporter of rock drilling tools, we presented our in-house developed fully automatic production line in a video at the exhibition. The highly-efficient production process caught the attention of numerous professional customers who stopped to watch and inquire. Additionally, our exhibition team, relying on their rich industry experience, patiently and professionally answered all the questions of customers, winning high praise from them and strong interest in our products.

During the exhibition, a great number of new customers expressed their willingness to cooperate on the spot. Meanwhile, many long-term cooperative customers visited our booth. Both sides had in-depth conversations about market development, technological innovation and service improvement. In the meantime, they highly praised the quality of our products and services and looked forward to the following cooperation.

BAUMA CHINA 2024 brought important opportunities for us to deepen cooperation and expand the market. We will continuously adhere to the core value that "Customer satisfaction and repeat business are the only standards for our work " and are committed to becoming your trusted partner in rock drilling tools.

1. Functions of DTH Drill Rods:

Delivery High Pressure Air: DTH drill rod is responsible for transporting high pressure air from the compressor to DTH hammer, which under pressure, drives DTH drill bit to break rock.

Transfer Lifting Force: DTH drill rods effectively transmits the rotary power (torque) of the drill rigs to DTH drill bit, driving it to rotate and cut through rock or soil.

Transfer Rotational Force: During drilling, DTH drill rods must withstand downward thrust from the drill rigs as well as reactionary forces caused by varying rock hardness.

Transport Flushing Media: The internal channel of DTH drill rods serves as a conduit for flushing media (such as water, air, or mud), which cools the drill bit, removes drill cuttings, and helps stabilize the borehole walls, enhancing drilling efficiency and quality.

2. Selection of DTH Drill Rods Diameter

Common diameters include 76mm, 89mm, 102mm, 114mm, 127mm, and 140mm. The diameter of DTH drill rods affects the up hole velocity and the efficiency of debris removal. A smaller diameter results in a larger annular space between the rod and the borehole walls, slowing the up hole velocity and thus affecting debris removal efficiency. Conversely, a larger diameter increases the up hole velocity and debris removal efficiency.

3. Selection of Wall Thickness for DTH Drill Rods

Common wall thicknesses are 76x4mm, 76x6mm, 89x6mm, 102x8mm, 114x8mm, 127x8mm, and 140x10mm. Wall thickness directly impacts the strength and durability of DTH drill rods. Thicker DTH drill rods have higher resistance to compression, tension, and torque, offering greater strength in handling complex geological conditions and hard rock layers, making them more suitable for shallow holes such as mining blast holes and shallow wells. However, their greater overall weight can lead to challenges in lifting and pressure issues in the drill rigs, making them less suitable for deep drilling.

Thin-walled DTH drill rods have lower torque, are lighter, easier to handle and operate, and are suitable for deep drilling like water wells or geothermal wells. However, their lower compressive and tensile strengths make them susceptible to thinning walls and reduced strength in harder rock layers, leading to potential fractures or deformations, thus, it's not recommended for high-strength drilling tasks.

4.Selection of DTH Drill Rods Length

Common effective lengths include 1.5m, 3.0m, 4.0m, and 6.0m. The choice of DTH drill rods length mainly depends on operational space and the feed length of the drill rigs.

5. Selection of Threads for DTH Drill Rods

Typical threads include API REG, such as API REG 2.3/8", API REG 2.7/8", API REG 3.1/2", API REG 4.1/2"; API IF threads are suitable for drilling deep water wells, e.g., API IF 2.3/8", API IF 2.7/8", API IF 3.1/2", API IF 4".

6. DTH Drill Rods with or without Wrench Flats

Sizes of  DTH drill rods with wrench flats generally include 76mm (57mm, 65mm), 89mm (65mm, 70mm), 102mm (83mm, 75mm), 114mm (89mm, 95mm), 127mm (89mm), and 140mm (114mm). DTH drill rods with wrench flats can be manually changed using a wrench. Some drill rigs come with a built-in wrench that also allows for changing drill rods through the wrench flats. DTH drill rods without wrench flats are suitable for drill rigs equipped with automatic rod carousel and are usually more expensive than those with wrench flats.

In practical drilling projects, it is necessary to select the appropriate DTH drill rods based on specific geological conditions and project requirements to achieve optimal construction results and economic benefits.

The friction welding process for DTH drill rods uses the heat generated by the friction at the contact surfaces of the workpieces, which under pressure causes plastic deformation, thus facilitating the welding.

1. Principle of Friction Welding

The principle of friction welding involves using the relative motion between the welding contact surfaces to generate friction heat and plastic deformation, raising the temperature around the contact area to near melting point. At this temperature, the material becomes more pliable and its resistance to deformation decreases. With this plastic deformation, the rod and joint under pressure join through interface recrystallization and molecular diffusion.

2. Friction Welding Process

Prepare DTH drill rod joint and body and align them to ensure co-axial alignment during welding. Start the friction welding machine to rotate the joint at a specific speed while applying axial pressure to the DTH drill rod body to begin friction heating. When the friction surfaces of the joint and rod body reach the welding temperature, stop rotation. Simultaneously with the cessation of rotation, apply greater axial pressure to perform forge press. Maintain this forge pressure for a period, then let the joint cool naturally to room temperature. After a period of cooling, the material in the weld joint re-solidifies to form a robust connection. After friction welding, the welded area of the DTH drill rod and joint often experiences defects such as poor mechanical properties and unstable microstructure. Therefore, it is necessary to carry out heat treatment of the weld area, specifically quenching followed by high-temperature tempering, to achieve a uniform and stable weld structure with good overall mechanical properties.

3.  Advantages of Friction Welding

1.  Short welding construction time and high production efficiency.

2.  High weld quality, typically free from weld spatter, with high post-weld dimensional accuracy.

3.  Welding does not produce smoke, arc light, or harmful gases, thereby avoiding pollution.

4.  High degree of mechanization and automation, consistent welding quality.

During drilling operations, DTH drill rods are subjected to various complex loads such as bending, twisting, compression, and tension, making safety paramount. Friction welded DTH drill rods exhibit strong bending resistance, good flexibility, and wear resistance, which contributes to their widespread application.

The friction welding process for DTH drill rods uses the heat generated by the friction at the contact surfaces of the workpieces, which under pressure causes plastic deformation, thus facilitating the welding.

1.  Principle of Friction Welding

The principle of friction welding involves using the relative motion between the welding contact surfaces to generate friction heat and plastic deformation, raising the temperature around the contact area to near melting point. At this temperature, the material becomes more pliable and its resistance to deformation decreases. With this plastic deformation, the rod and joint under pressure join through interface recrystallization and molecular diffusion.

2. Friction Welding Process

Prepare DTH drill rod joint and body and align them to ensure co-axial alignment during welding. Start the friction welding machine to rotate the joint at a specific speed while applying axial pressure to the DTH drill rod body to begin friction heating. When the friction surfaces of the joint and rod body reach the welding temperature, stop rotation. Simultaneously with the cessation of rotation, apply greater axial pressure to perform forge press. Maintain this forge pressure for a period, then let the joint cool naturally to room temperature. After a period of cooling, the material in the weld joint re-solidifies to form a robust connection. After friction welding, the welded area of the DTH drill rod and joint often experiences defects such as poor mechanical properties and unstable microstructure. Therefore, it is necessary to carry out heat treatment of the weld area, specifically quenching followed by high-temperature tempering, to achieve a uniform and stable weld structure with good overall mechanical properties.

3.  Advantages of Friction Welding

1. Short welding construction time and high production efficiency.

2. High weld quality, typically free from weld spatter, with high post-weld dimensional accuracy.

3. Welding does not produce smoke, arc light, or harmful gases, thereby avoiding pollution.

4. High degree of mechanization and automation, consistent welding quality.

During drilling operations, DTH drill rods are subjected to various complex loads such as bending, twisting, compression, and tension, making safety paramount. Friction welded DTH drill rods exhibit strong bending resistance, good flexibility, and wear resistance, which contributes to their widespread application.

In the early applications of anchor bolt support technology, foreign countries used ordinary rock drilling machines for drilling anchor holes and installed anchor bolts manually, tightening nuts with wrenches. In 1950s, the United States introduced the first anchor drill rig, marking the beginning of the mechanization era of anchor bolt support technology. By the late 1950s, with continuous improvements in anchor bolt support theory and design methods, countries like the UK began applying anchor bolt support technology in coal mine roadway support. To suit the smaller cross-sectional area of coal mine roadways, the UK, Poland, and other countries developed single-unit electric and hydraulic rotary anchor bolt drill rigs.

During the 1960s and 1970s, as mines and tunnel projects increasingly emphasized anchor bolt support methods, anchor drill rigs entered a period of rapid development. During this period, the GARDNER DENVER company developed a crawler-based drill rig-style anchor drill rig in 1964, which laid an important foundation for the development of anchor drill rigs. Subsequently, the BUMUELLER company further improved the moving structure, designing it as a more convenient hub-style structure that enhanced the mobility and flexibility of the anchor drill rigs. In the 1970s, significant breakthroughs were also made in terms of rig-mounted anchor drill rigs. In 1972, the BENDIX company of the USA first attempted to mount an anchor drill rig on a tunneling machine, achieving integration of drilling and excavation. This innovation not only increased the efficiency of anchor bolt supports but also paved the way for the widespread application of anchor drill rigs in mining and tunnel engineering.

From the 1980s to the 1990s, Australia successfully developed a lightweight leg-type pneumatic anchor drill rig, which has been widely used in coal mines in Australia, the UK, China, Poland, and India. This type of drill rig uses an air motor for cutting power, and the advancement legs are made of high-strength glass fiber and carbon fiber, characterized by singular power, light weight, and high output torque. It is used not only for the construction of anchor and anchor cable holes but also for mixing resin anchor bolts and tightening nuts, and it remains a principal model of single-body anchor drill rigs worldwide.

During the 1990s, companies like Jeffrey and Joy from the USA, and Anderson from the UK, developed rig-mounted anchor drill machines in combination with continuous miners and tunneling machines, achieving a new generation of integrated mining and drilling operations. These latest anchor drill rigs not only utilize new materials and processes but also employ computer control technology, significantly advancing the mechanization and intelligence of anchor bolt construction, enhancing performance, convenience, and safety.  In 1990, Voestalpine from Austria first mounted an anchor drill rig on a continuous miner, further promoting the integration of coal mining and drilling and advancing the development of anchor drill rig technology.

As high-tech continues to evolve, anchor drill rigs and their complementary drill tools are constantly being improved and innovated. Anchor drill rigs are moving towards multifunctional, integrated rig-mounted directions.

Meanwhile, anchor bolt drilling rigs have also developed three main categories based on their power source: hydraulic, pneumatic, and electric, with hydraulic and pneumatic anchor drill rigs dominating the international scene. These various types of anchor drill rigs each have their characteristics, suitable for different engineering environments and needs. Anchor drill rigs are playing an increasingly important role in mining and tunnel engineering. In the future, as technology continues to advance and innovate, anchor drill rigs will face a broader development prospect.

Exhibition Name: BAUMA China 2024
Booth Number: E5.368
Exhibition Time: NOV. 26 - 29, 2024
Exhibition Venue: The Shanghai New International Expo Centre (SNIEC) 

During the exhibition, we've arranged full-day reception. We look forward to face-to-face discussions with you to explore cooperation. We value every meeting with you as it's a key chance to enhance mutual understanding and trust. We're eager to hear from you and know your needs to start new cooperation.

We are looking forward to your visit. Let's meet at booth E5.368 and collaborate for a more prosperous future.

1. Early Applications of Anchoring Technology

In 19th century, anchoring technology patents were first applied and developed abroad. Since 1872, when a surface shale mine in North Wales, UK, first used rock bolts to reinforce slopes, rock bolting has gradually been promoted. The United States began using rock bolts to support mine tunnels in 1911. In 1912, the Scherz mine in Germany was the first to use rock bolts to support underground tunnels. In 1934, during the second phase of the heightening project of the Chervas Dam in Algeria, prestressed rock bolts with a load capacity of 10,000 kN were used for the first time to maintain the stability of the rear dam body. This was the first successful use of tightening anchor bolts to reinforce a dam body in the world, and subsequently, prestressed rock bolts were widely used in dam reinforcement.

2. Promotion and Technological Innovation in Anchoring

From the 1950s to the 1970s, the application of anchoring technology rapidly expanded. In 1957, the Bauer Company of the former Federal Republic of Germany used soil anchors in the deep foundation pit of the Bavarian Broadcasting Corporation in Munich. At this time, rock bolts had become an important means of controlling construction safety in underground excavation projects in Germany, Austria, and other countries. In the 1960s, countries such as Czechoslovakia and Germany adopted a combination of high prestressed long anchor bolts and low prestressed short anchor bolts in large underground cavern projects. In 1974, the New York World Trade Center deep excavation project used anchoring core technology, with 6 rows of anchors bolts pulled back at an inclination angle of 45° and a working load of 3,000 kN. Subsequently, countries such as Switzerland, Czech Republic, the United Kingdom, the United States, Brazil, Australia, and Japan widely adopted rock bolt support to maintain slope stability. In the 1980s, the UK, Japan, and other countries developed new technologies for single-hole composite anchoring, which improved the force transmission mechanism of rock bolts and increased their load capacity and durability. In 1987, the UK introduced a complete set of rock bolt support technology from Australia, and coal roadway rock bolt support developed rapidly.

3. Further Advancements in Anchoring Technology

After the 1990s, theoretical research, technological innovation, and engineering applications of geotechnical anchoring further advanced and improved. Theoretical studies mainly focused on the load transfer mechanisms of strata anchoring and the adhesion and distribution between different types of grouted rock bolts, the grout, and the strata. This period witnessed especially active international discussions and exchanges on rock bolt technologies. Between 1995 and 1997, international symposiums focusing on strata anchoring and anchorage structures were held in Austria, China, and the UK respectively, significantly promoting the development of anchoring technology.

4. History of Anchoring Technology in China

In China, rock bolts support began in the 1950s, with extensive application in mine tunnels, railway tunnels, and various other underground constructions starting in the 1960s. In 1964, the foundation of Meishan Reservoir Dam in Anhui first adopted high-tonnage prestressed anchor cables. Over the past few decades, anchoring technology in China has rapidly developed and been broadly used in various civil engineering such as slopes, pits, tunnels, underground projects, dams, docks, coasts, and bridges. Large projects like the Three Gorges Hydraulic Hub, the Western Coastal Highway of Guangdong, Jing-Fu Expressway, Jinan Bypass, Hainan East Line Expressway, and Longtan Hydropower Station have extensively used prestressed anchor cables.

With continuous scientific and technological progress and the accumulation of practical engineering experience, anchoring technology is constantly being innovated and developed. In the future, anchoring technology will focus more on environmental protection, efficiency, and intelligence. Filled with innovation and practical application, anchoring technology will continue to play a significant role in the construction projects of humanity.

1. Pneumatic Rock Drilling Tools

In the 1940s, cemented carbide rock drilling tools were put into use, showing high-efficiency drilling effects. Alongside the increase of various military and infrastructure construction projects, pneumatic rock drills developed rapidly. The production and development of 19mm, 22mm and 25mm hexagonal integral drill rods, tapered drill rods,  chisels with cross and X-type tapered drill bits also received significant attention.

Since the 1950s, rock drilling tool companies abroad invested considerable effort in material selection, manufacturing processes, equipment, and drilling tests to significantly enhance the performance and lifespan of 22mm hex rods and bits.  From the early 1970s, as industrialized countries experienced rapid economic growth and increased demand for drilling projects, more efficient and energy-transferable hydraulic rock drills emerged and quickly became widespread. This led to a significant decline in the use of pneumatic rock drills, reducing market demand for 22 mm hex tools. By the mid-1980s, these lightweight drilling tools were no longer the primary products in rock drilling projects.

2. Hydraulic Rock Drilling Tools

From the mid-1970s, foreign rock drilling tool manufacturers shifted their main focus to developing drilling tools for hydraulic drilling rigs. By the early 1980s, a series of drilling tool products for hydraulic drilling rigs had basically been formed, including drill rods and button bits for hydraulic tunneling drill jumbos and hydraulic mining drill jumbos, extension rods for open-pit hydraulic drill jumbos, medium and large diameter button bits, and shank adapters for hydraulic rock drills. These products continually improved in quality, variety, and performance to meet the demands of that era’s hydraulic rock drills.

Since the mid-1980s, with industry development, hydraulic drills evolved towards higher impact power and greater torque to achieve faster drilling rates. In the mid-1990s, modern hydraulic drills significantly outperformed earlier models, leading to increased demands on compatible rock drilling tools. Major foreign rock drilling tool manufacturers conducted extensive research on steel materials, enhancing carbide button bits’ toughness, and improving thread connections to enhance impact energy transfer. Today, the focus of foreign rock drilling tool research is on high efficiency, low energy consumption, and longevity.

3. DTH Drilling Tools

In the mid-1950s, DTH drilling tools began to be applied to rock drilling projects. In the 1960s, the American company Hughes implemented tricone bit technology in producing DTH button bits. Meanwhile, medium and low-pressure DTH drilling technologies were substantially developed and widely used in surface operations, becoming the preferred choice for medium and large diameter drilling operations of that time. By the mid-1970s, as hydraulic drill rigs increasingly dominated the market, high-efficiency hydraulic rock drills overshadowed DTH drilling tools in performance.  Therefore, the development of DTH drilling tools was relatively slow during this period. Beginning in the 1980s, Atlas Copco and Ingersoll-Rand began to introduce high-pressure DTH hammers to the market. Compared with medium and low-pressure hammers, high-pressure DTH hammers have higher drilling efficiency. Recognized for their unique properties in surface rock drilling projects, high-pressure DTH drilling tools rapidly developed.

By the 1990s, with the advancement of high-pressure DTH drill rigs, DTH drilling tools began to show advantages, and their application fields expanded from surface mining to slope stabilization, anchor drilling, quarrying, and various underground projects. Into the 21st century, with technical advancements, DTH drilling tools have become simpler in internal structure, easier to maintain, and more efficient, gaining widespread attention in the rock drilling industry.

As a professional manufacturer of rock drilling tools, SINODRILLS produces a wide range of pneumatic, hydraulic, and DTH drilling tools. We maintain a strict quality control system and offer comprehensive after-sales service. Our products have been exported to over 110 countries and are widely used in mining, quarrying, ground support, mineral exploration, water well, and geothermal drilling projects.

1. The birth of hydraulic rock drills

In 1920, the Britishman Dorman developed a hydraulic rock drill. About 40 years later, another Britishman Suttcliffe developed another type of hydraulic rock drill, but neither was sold on the market. In the late 1960s, French Secoma company developed the RPH-35 hydraulic rock drill for laboratory drilling. In 1970, French Montabert launched the world’s first practical hydraulic rock drill, model H50, which achieved excellent results of 14,000m of drilling and was put into mass production and application. Since then, dozens of rock drilling equipment manufacturers from France, Sweden, Finland, Germany, Austria, the United Kingdom, the United States, Japan, as well as Poland have competed to research and develop distinctive hydraulic rock drills and fully hydraulic drilling equipment.

2. Hydraulic rock drills at the end of the 20th century

As various countries successively developed and launched various models of hydraulic rock drills into the market, the advantages of low energy consumption, rapid drilling speed, long component life, and lower consumption of drilling tools were proven in practice. Companies continually improved and perfected their designs, enhancing the reasonableness of the hydraulic rock drill design and its performance.

By the late 20th century, hydraulic rock drills were adapted to drill holes with diameters ranging from Ø 27 to Ø 230mm, with the heaviest Tamrock’s HL4000 model weighing 1100 kg.  During this period, the service life of hydraulic rock drills also greatly improved. The service life of the impact piston of Tamrock’s second-generation hydraulic rock drill was 500 impact hours, while the third-generation product reached 1,000 impact hours; the maintenance cycle of Atlas Copco’s COP1238 hydraulic rock drill was 100-200 hours, while the COP1838 reached more than 500 hours.

3. Hydraulic rock drills in the 21st century

Entering the 21st century, the needs of drilling project and the advancement of hydraulic rock drills have given hydraulic rock drills good development prospects.

The mechanical rock-breaking method for tunnels and roadways is also called the TBM method. Abroad, 30%-40% of tunnels are constructed using the TBM method each year.  However, since the TBM method is only effective in tunnels longer than 2,000 m, most tunnels are still constructed using the drilling and blasting method. The experience of using hydraulic rock drills in tunnel drilling and blasting has proven that hydraulic rock drills are key equipment for improving tunnel construction speed and conditions, and they will continue to play a role in tunnel project in the future.

In mining and surface drilling projects, where extensive and robust rock work is required, drilling and blasting is almost the only effective rock-breaking method, and highly efficient and economical rock-breaking equipment must be hydraulic rock drills and their supporting hydraulic drill jumbos.

The successful application and development of hydraulic rock drills have also brought changes in the mechanization of non-blasting hole construction, improving the level of rock hole construction such as anchor bolt holes, water exploration holes, and grouting holes.

Nowadays, with the development of microelectronic technology, remote control technology, navigation technology, underground global positioning system (UGPS) technology, and automatic operation technology, hydraulic drilling equipment is developing towards higher-level remote control and intelligence, and will become an important intelligent equipment for the construction of unmanned mines.

DTH drill bits and hammers use compressed air to generate impact energy, driving the drill bit to perform drilling operations. The DTH hammer contains a precise air distribution system consisting of an air distributor , internal cylinder, piston, and piston case. Its working principle involves entering compressed air into the DTH hammer, causing the piston to reciprocate within this system, converting air energy into mechanical energy, and ultimately transmitting it to the drill bit to break the rock.

1.  DTH Hammers for DTH Bits with Foot Valve:

Blow tube, plastic tube, tube, foot valve, all refer to the same item.

Regular DTH product series with foot valve include:

DHD series: DHD3.5, DHD340, DHD350, DHD360, DHD380

QL series: QL40, QL50, QL60, QL80

SD series: SD4, SD5, SD6, SD8

COP series: COP34, COP44, COP54, COP64, COP84

In these DTH hammers, the foot valve works in conjunction with the piston based on a sealing principle, acting as a valve within the hammer to control air distribution. Typically, these DTH hammers have a heavier and shorter piston with more space in their air distribution system. This configuration allows for a lower impact frequency yet greater force per impact under the same air pressure, making them suitable for very hard rock formation. 

Additional advantages of DTH hammers for DTH bits with foot valve include:

1.   Airflow Control:  

The foot valve adjusts the flow of compressed air entering the hammer. As the piston moves down, it allows air into the hammer, thus forming a high-pressure zone. This high-pressure air is then released through the drill bit, producing the necessary impact force to break rock.

2.   Pressure Maintenance:

The foot valve helps maintain the necessary pressure inside the hammer. Proper pressure control ensures efficient operation of the hammer and provides the required impact energy to the drill bit. It also prevents pressure overloads, which can damage equipment or reduce drilling efficiency.

3.   Directional Control:

In some DTH hammers, the foot valve also acts as a directional control. It directs airflow to different parts of the hammer, allowing the piston to move and ensuring the correct transference of impact energy to the drill bit.

2.  DTH Hammers for DTH Bits without Foot Valve:

Regular DTH product series without foot valve include:

Mission series: Mission 30, Mission40, Mission 50, Mission 60, Mission 80.

COP series: COP32, COP42, COP52, COP62.

BR series: BR2, BR3, BR4.

DHD-N series, improved series based on DHD : DHD2.5N, DHD3.5N, DHD340N, DHD350N, DHD360N, DHD380N.

QL-N series, improved series based on QL : QL50N, QL60N, QL80N.

In these hammers, the smaller lower end of the piston interacts with a guide sleeve, taking on the role of the foot valve. Unlike the DTH hammers with a foot valve, these have a longer piston and a more compact air distribution system, resulting in a shorter piston stroke, faster impact frequency, and less force per impact. Therefore, non- foot valve DTH hammers are more suited to soft or medium soft rock formation .

Additional advantages of DTH hammers for DTH bits without foot valve include:

1.   High drilling speeds, the drilling speed is 15%-30% higher than the one with foot valve.

2.   Out of issues due to foot valve breakage, damage, and thermal expansion and contraction.

3.   Lower air Consumption, reduced fuel consumption: over 10% savings compared to DTH hammers with foot valves.

4.   Simpler internal structure, lower overall failure rate, less frequent dismantling, reduced downtime for clients.

Clients should choose the most suitable DTH product series based on the rock conditions they need to drill, and can also consult the Sinodrills sales team in advance.

We not only provide reliable products, but also offer professional guidance and suggestions!

1. Birth of DTH Hammers

In 1857, Italian engineer Bartritt invented the world’s first pneumatic rock drill powered by compressed air, marking a new era in DTH drilling. In 1932, Ingersoll-Rand in the USA invented DTH hammer, characterized by delivering the drill machine to the bottom of the hole, thus reducing energy loss, and it began being used in surface mining by the late 1940s. In 1951, Belgian engineer Andre Stenuick designed and manufactured a DTH hammer, which was similar in structure to modern DTH hammers.

2. Rapid Development of DTH Hammers

Ingersoll-Rand played a world-leading role in developing new fields and types of pneumatic DTH hammers. In 1955, the company introduced a new downhole drill design and began truly commercializing downhole drilling. The technology underwent rapid changes in the 1960s and 1970s. Ingersoll-Rand quickly developed the DHD 325 (their first 6-inch DTH hammer), DHD 325A, DHD 16, DHD 1060, DHD 1060 A and B models, DHD 360, and corresponding larger and smaller models, up to the current DHD series.

A significant change in DHD technology was the introduction of valveless DTH hammers. Early DTH hammers had valves, and practice proved that the drilling speed of DTH hammers largely depended on the pressure of compressed air, higher pressure results in greater drilling speed. The change to valveless DTH hammers was made to reduce the consumption of compressed air when using high-pressure compressed air. Valveless DTH hammers consume less air because they do not need to fill the space between the inner cylinder and the wear-resistant casing with compressed air to activate the check valve for each impact. In addition, valveless DTH hammers rely on the movement of the piston for automatic air distribution, the only moving part is the piston, which has a simple structure, easy maintenance, and good performance.

Valveless DTH hammers have been widely tested in the UK and other countries, and compared with valved DTH hammers, the mechanical drilling speed remains high, and the service life is extended.

3. Development of High Pressure DTH Hammers

As the application field of DTH hammers continuously expanded, to solve drilling efficiency issues in very hard and abrasive rocks, the air pressure used in DTH hammers has been increasingly higher. The air pressure of general DTH hammers is roughly below 1.4 MPa, while high-pressure DTH hammers range from 1.7 to 2.47 MPa.

In 1986, Halifax in the UK introduced the Mach 400 turbine high-pressure valveless DTH hammer, which could work with air pressures up to 3.5 MPa. It was widely tested and used extensively in Scandinavia for drilling very hard and abrasive rock formations, demonstrating reliable performance and substantial mechanical drilling speeds.

Practice has proven that drilling speed is positively related with compressed air pressure. With the development of air compressor technology, the air pressure that can be used by DTH hammers is getting higher and higher.

4. Development of water-powered DTH Hammers

Beyond compressed air, exploring other mediums for powering DTH hammers has been ongoing. In the early 1980s, Sweden’s Atlas Copco began developing water-powered DTH hammers, and G-Drill continued this research, collaborating with Sweden’s LKAB in 1988. After two years, they finally developed the Wassara water-powered DTH hammer. During its first test at an LKAB-owned iron ore mine in spring 1990, approximately 500,000 meters were drilled, showing several advantages: capable of drilling at any angle, require 10% less power, increased penetration rates by 2.5 to 3 times, and improved working conditions, showing a great development prospects in certain applications.

Today, DTH hammers are widely used at surface and underground mines, quarries, hydroelectric projects, water well drilling, mineral exploration, geothermal extraction, subway construction, and other projects. Due to its high drilling accuracy, smooth borehole walls, unrestricted drilling depth, and ease of maintenance, it has gained wide attention in the rock drilling industry.

Sinodrills produces a wide range of DTH hammers, our DTH hammers have the advantages of simple internal structure, low air consumption, and high penetration rate. They are currently widely used in water wells, geothermal wells, quarrying, mining, foundation piles, and other projects in Europe and Australia.

1. The Start of Mechanized Rock Drilling

During the long social development, hand hammer drilling was once the main method of rock drilling. As social production demands increased, people began seeking mechanical methods.

In 1813, the British R. Treuithick invented the first steam powered rock drill, opening the way for the development of rock drilling machines.

The earliest steam powered rock drill had a similar working principle to a steam engine. A piston moving in a straight line through the cylinder, changing the direction of the intake and exhaust through a sliding valve, thus the drill rod and the drill bit connected to the piston are driven to impact the rock. This basic principle is still widely used today.

However, the steam temperature is high, which makes it inconvenient to use, and the long pipeline has the problem of cooling, so compressed air soon replaced steam for rock drills and pneumatic rock drills appeared.

2. Birth and Development of Pneumatic Rock Drills

In 1844, the British Brunton invented the compressed air powered rock drill, but the design had many issues and was not practically applicable. By 1857, Italian engineers Bartlett and German-Samet improved on previous research and designed a practical rock drill powered by compressed air, first used in the tunnel through Senni Peak in the Alps, marking that year as the birth of the rock drill. 

Continuous improvements during that period included separating the piston from the drill rod, laying the foundation for modern rock drills, and transitioning to hollow drill rods that could be flushed with high-pressure air or water. Other enhancements to components like rotary mechanisms and air distribution valves significantly improved drilling efficiency.

As the power of rock drills continued to increase, air-leg rock drills can no longer meet production requirements. Meanwhile, in order to reduce the physical exertion of operators, column-supported rock drills appeared. In the 1950s, a variety of self-propelled pneumatic rock drills appeared. In Europe and North America, many companies have entered the field of pneumatic rock drills, among which Sweden's Atlas Copco and the United States' Ingersoll Rand are two of the leaders.

3. Development and Maturity of Hydraulic Rock Drills

Pneumatic rock drills have simple structures, are easy to manufacture and maintain, and are widely used. They play a huge role in the production process. However, as the hole depth continues to increase, people have found that the drill rod joint will lose a lot of impact energy. At the same time, there are fatal shortcomings such as high noise and large oil mist. In order to solve this problem, people have been exploring new energy transfer media. By the 1920s, a hydraulic rock drill was developed in Britain, but industrial and hydraulic technology limitations at the time hindered its production.

In 1960s, various hydraulic rock drill patents emerged and several companies began their development.

In 1970, the French company Montabert create the first generation producible hydraulic rock drill. Following this, the USA, Sweden, the UK, Germany, Finland, Austria, Switzerland, and Japan developed various models and launched them into the market, leading to rapid technological advancements due to more companies entering the hydraulic rock drill field. The benefits of hydraulic rock drills became increasingly clear: they not only significantly reduced energy consumption but also improved drilling speeds and working conditions. By the 1980s, after continuous improvements, hydraulic rock drills matured, became serialized, and started replacing pneumatic rock drills in many applications. In the 1990s, hydraulic rock drills developed towards greater power and higher drilling speeds, resulting in the development of corresponding fully hydraulic tunneling and mining drill rigs. Automation and remote control began being implemented, and entering the 21st century, further advancements in automation and intelligence have been made, with today’s high-end intelligent drill rigs integrating various advanced technologies and featuring high levels of automation capabilities.

Air pressure is the power source for DTH hammers during operation, directly determining their efficiency and drilling speed. Based on the working air pressure, DTH hammers can be categorized into low pressure, medium pressure, and high pressure types. This classification is primarily based on the air pressure level used by DTH hammers, with different pressure levels suited for various working environments and drilling needs.

1. Low Pressure DTH Hammers 

The working air pressure range for low pressure DTH hammers is usually below 7 Bar. Common model is CIR series, including CIR 65, CIR 70, CIR 80, CIR 110, CIR 150, and CIR 170.

Low pressure DTH hammers use compressed air as their power source, utilizing the impact force of the air to break underground rocks. These hammers have lower requirements for air compressors, and contain fewer internal components. Due to their lower working pressure, the impact force produced is also lower, which results in slower drilling speeds, thus allowing for more precise drilling.

The energy consumption of low pressure DTH hammers is relatively low, in situations where drilling speed is not highly demanding or where the rock formations are softer, low pressure DTH hammers are often competent and offer better cost-effectiveness.

Low-pressure DTH hammers are widely used in soil exploration, water well drilling, and small-scale construction projects.

2. Medium Pressure DTH Hammers

The working air pressure range for medium pressure DTH hammers is approximately 7 bar to 14 bar. Common models are BR2 and BR3. Compared to low-pressure DTH hammers, medium pressure hammers offer better drilling efficiency and speed, allowing for deep hole drilling generally used in larger-scale construction projects.

3. High Pressure DTH Hammers

The working air pressure range for high pressure DTH hammers is approximately above 14 bar, with the maximum pressure reaching around 35 bar.

With advancements in air compressor technology, the working air pressures of high pressure DTH hammers have been increasing, and even some small diameter DTH hammers can be used as high pressure hammers now.

Common high pressure DTH hammer models include:

DHD series: DHD3.5, DHD340, DHD350, DHD360, DHD380;

QL series: QL40, QL50, QL60, QL80; SD series: SD4, SD5, SD6, SD8; Mission series: Mission 30, Mission 40, Mission 50, Mission 60, Mission 80;

COP series: COP32, COP34, COP42, COP44, COP64, COP84.

High pressure DTH hammers use high pressure gases as a power source, with the gas explosion reaction producing high-speed impact forces to break the rocks. These hammers generally require larger air compressors to provide sufficient working pressure, and their design also emphasizes impact force and wear resistance.

Due to their high working pressure, they can generate a greater impact force, effectively breaking hard rocks, which enhances drilling efficiency in tough rock conditions.

High-pressure DTH hammers are widely used in mining, hydraulic engineering, road construction, and geological exploration.

In practical DTH drilling applications, it is necessary to consider factors such as specific project requirements, rock characteristics, environmental conditions, and budget constraints comprehensively.

Choosing the most suitable DTH hammers is the key to ensure the smooth progress of the drilling process, improve drilling efficiency and reduce operating costs.

The working principle of  DTH button bits involves transmitting stress impact waves generated by DTH hammers to continuously high-frequency impact the rock surface. The rock cracks and breaks under the impact, and is directly cut off under the rotary action of the DTH drill pipe. And with the action of high-pressure airflow, the broken rock cuttings is continuously blown out of the hole, thereby achieving the purpose of drilling.

During the drilling process, the carbide buttons of DTH button bits mainly bear the high-frequency stress waves from DTH hammers, directly transmitting the high-frequency stress waves to the rock surface and participating in the cutting work. The carbide buttons of DTH button bits experience very complex stress conditions during operation, making it particularly important to choose the right button shape.

Commonly used carbide button shapes of DTH button bits include conical buttons, ballistic buttons, semi-ballistic(parabolic) buttons, and hemispherical(dome) buttons.

1. Conical Buttons

Conical buttons have a sharp shape, so they have a small contact area with rock, less resistance, and faster drilling speed. However, due to their slimmer volume, the carbide buttons have relatively poor bending and torsion resistance. The exposed buttons height is relatively high after inserting, which can generate significant bending moments during operation, making the carbide buttons easy to breaking.

The greatest advantage of conical buttons is their fast drilling speed, suitable for all soft rocks and low-abrasive rock formations.

2. Ballistic Buttons

Ballistic buttons evolved from conical buttons, enhancing the structural flaws of conical button shapes, effectively improving the bending and torsion resistance of the carbide buttons, thereby extending the button life. They also combine the advantages of conical buttons, achieving fast drilling speeds.

Ballistic buttons are most suitable for soft rock, medium-soft rock, and low-abrasive rock formations. They offer faster drilling speed and higher rock-breaking efficiency than hemispherical buttons, but they are not very suitable for broken rock formations, as they may break easily.

3. Semi-ballistic (Parabolic) Buttons

Semi-ballistic buttons have a fuller shape compared to ballistic buttons, making them more wear-resistant. These button shapes balance the durability of hemispherical buttons with the high rock-breaking speed of ballistic buttons, suitable for medium-hard or medium-abrasive rock formations.

4. Hemispherical (Dome) Buttons

Hemispherical buttons possess excellent bending and torsion resistance, unmatched in impact toughness and strength compared to other button shapes. Due to their fuller crown, the allowable wear on carbide buttons is relatively increased, extending the service life significantly. 

They are widely used in various working air pressures, various rock hardness geological structures, especially in high air pressure fields exceeding 1.6MPa and complex geological environments with interlayers and cracks.  However, the carbide buttons have a large contact area with the rock surface when working, generating high friction resistance, thus resulting in a slower drilling speed.

Hemispherical buttons are the most commonly used shape in DTH drill bits and are most suitable for hard rock and highly abrasive rock formations.

Each shape of carbide buttons has its own scope of use and work characteristics. When selecting, clients should consider factors such as rock hardness, geological structure, and engineering requirements to choose the suitable button shape to ensure smooth progress of the drilling project!

The heat treatment methods for tapered drill rods include high-frequency induction and carburization heat treatment.

1.     High Frequency Induction

High-frequency induction is a method to heat and cool the surface of raw material by high-frequency current to obtain the surface hardened layer.  This method only strengthens the surface to a certain depth, while the core largely retains its pre-treatment structure and properties. The heating process in high-frequency induction typically takes only a few seconds to complete, thus significantly reducing quenching deformation and lowering energy consumption. High-frequency induction is suitable for various structural steels.

The process is to preheat the raw material first, then heating the surface of the raw material with high-frequency current to the quenching temperature, followed by rapid cooling to form a surface-hardened layer. Then annealing is performed to eliminate quenching stress and maintain the overall performance of the raw material. Finally tempering, further adjust the hardness, improve the toughness of raw materials.

In general, only the shank and tapered end of the tapered drill rod undergo high-frequency induction, increasing the strength of both ends, while the body of the tapered drill rod remains its original toughness. This type of tapered drill rod is more flexible and suitable for softer geology and surface as well as loose rock layers. Under certain conditions, high-frequency induction hardened tapered drill rods are more economical.

2.     Carburization Heat Treatment

Carburized taper drill rod is usually made of low carbon alloy steel (with carbon content less than 0.25%). This process mainly increases the carbon content of the surface and core hole surface of tapered drill rods body through chemical heat treatment, creating a carbon concentration gradient from the surface inward of a certain thickness. By quenching and tempering, the surface layer of the tapered drill rods achieves high hardness and wear resistance, while the center part retains the toughness and plasticity of low-carbon steel.

The process of carburization is to put the raw material into a carburizing furnace, heating it to about 900-920°C, and maintaining it for sufficient time, allowing the active carbon atoms decomposed from the carburizing medium to penetrate the surface layer of the raw material.

Carburized tapered drill rods receive a case hardness layer externally and internally (Flushing hole), providing rigidity and surface resilience to the entire tapered drill rod. This type of tapered drill rods has a stronger resistance to bending and can transmit higher torque and stress loads in demanding conditions. The carburization process also extends fatigue life and provides corrosion resistance, making the carburized tapered drill rod suitable for various complex geological conditions, especially in underground or tunnel drilling.

Overall, high-frequency induction hardened tapered drill rods are more economical and can be chosen for drilling in softer or more loose rock layers. If the geological conditions are complex and require high hardness and wear resistance in the tapered drill rods, then carburized tapered drill rods can achieve much better performance.

The crucial component of the self-drilling anchoring system is the self drilling anchor bars, which is divided into R thread and T thread. R-type threads feature continuous corrugated profiles, typically designed according to ISO 10208 or ISO 1720 standards, with common sizes being R25, R32, R38, R51, etc. T-type threads are usually based on internal designs of each manufacturer and do not conform to any international standard, with common sizes including T30, T40, T52, T73, T76, T103, T111, etc.

There are 3 ways to produce self -drilling anchor bars: cold rolling, hot rolling, and warm rolling.

1.    Cold Rolling

Widely used in European countries, this process employs low-carbon alloy steel pipes as raw material. Low-carbon alloy steel pipes inherently has lower hardness and strength but better plasticity, allowing it to be rolled at room temperature without heating. This rolling process refines the grain structure. As heating is not required, this method is more energy-efficient and environmentally friendly, and the quality is relatively stable. However, since it does not undergo heat treatment, the strength of the self-drilling anchor bars primarily depends on the strength of the steel pipes. To achieve adequate load capacity (mainly tensile and yield strength), these self-drilling anchor bars must maintain sufficient thickness, meaning a relatively heavier weight per meter or larger section area.

2.    Hot Rolling

Evolving from cold rolling process, hot rolling is mainly used in countries like China, Turkey, Iran, and India. The self-drilling anchor bars formed by hot rolling generally use medium-carbon alloy steel pipes. Unlike cold rolling, hot rolling requires the raw material to be heated above the phase transition temperature (around 1000℃) before rolling, followed by rapid water cooling, essentially an incomplete quenching process. While this method enables the production of stronger self-drilling anchor bars with thinner steel tubes, it compromises the ductility of the self-drilling anchor bars. The self-drilling bars are stronger but less plastic and more brittle with a lower elongation rate. Furthermore, the equipment used in this process is often primitive, and due to large temperature variances in the environment, it’s challenging to control the exact temperature changes, leading to inconsistent dimensions and quality of the self-drilling anchor bars. If the quality requirement for self-drilling anchor bars is not high,, hot rolling can be economically beneficial for use in temporary support project, but is unsuitable for permanent project.

3.    Warm Rolling

Warm rolling is an intermediary process between cold and hot rolling, usually also utilizing medium-carbon steel pipe as the raw material. This method requires heating the raw material to about 500℃ for rolling. It optimizes the properties of the steel pipe, balancing and ensuring strength while also achieving good ductility of the self-drilling anchor bars. Additionally, as the heating temperature is not very high, the dimensional control of the self-drilling anchor bars is more precise, and the quality is stable. Thus, warm rolling allows for an excellent balance between the toughness and ductility of self-drilling anchor bars, achieving superior overall mechanical properties.

As a professional manufacturer with over 20 years of production experience, Sinodrills possesses 8 full automated self-drilling anchor bars production lines. Our self-drilling anchor bars are dimensionally precise and consistently high-quality, ensuring strength and excellent toughness, fully reaching European standards, in some aspects even exceeding European standards. Our products are now widely used in railway, tunnel, rock bolting, infrastructure, and mining projects across Europe!

Anchor down your next project with Sinodrills’self -drilling anchor systems!

DTH drill bits and hammers use compressed air to generate impact energy, driving the drill bit to perform drilling operations. The DTH hammer contains a precise air distribution system consisting of an air distributor , internal cylinder, piston, and piston case. Its working principle involves entering compressed air into the DTH hammer, causing the piston to reciprocate within this system, converting air energy into mechanical energy, and ultimately transmitting it to the drill bit to break the rock.

1.  DTH Hammers for DTH Bits with Foot Valve:

Blow tube, plastic tube, tube, foot valve, all refer to the same item.

Regular DTH product series with foot valve include:

DHD series: DHD3.5, DHD340, DHD350, DHD360, DHD380

QL series: QL40, QL50, QL60, QL80

SD series: SD4, SD5, SD6, SD8

COP series: COP34, COP44, COP54, COP64, COP84

In these DTH hammers, the foot valve works in conjunction with the piston based on a sealing principle, acting as a valve within the hammer to control air distribution. Typically, these DTH hammers have a heavier and shorter piston with more space in their air distribution system. This configuration allows for a lower impact frequency yet greater force per impact under the same air pressure, making them suitable for very hard rock formation.  

Additional advantages of DTH hammers for DTH bits with foot valve include:

1.   Airflow Control:  

The foot valve adjusts the flow of compressed air entering the hammer. As the piston moves down, it allows air into the hammer, thus forming a high-pressure zone. This high-pressure air is then released through the drill bit, producing the necessary impact force to break rock.

2.   Pressure Maintenance:

The foot valve helps maintain the necessary pressure inside the hammer. Proper pressure control ensures efficient operation of the hammer and provides the required impact energy to the drill bit. It also prevents pressure overloads, which can damage equipment or reduce drilling efficiency.

3.   Directional Control:

In some DTH hammers, the foot valve also acts as a directional control. It directs airflow to different parts of the hammer, allowing the piston to move and ensuring the correct transference of impact energy to the drill bit.

2.  DTH Hammers for DTH Bits without Foot Valve:

Regular DTH product series without foot valve include:

Mission series: Mission 30, Mission40, Mission 50, Mission 60, Mission 80.

COP series: COP32, COP42, COP52, COP62.

BR series: BR2, BR3, BR4.

DHD-N series, improved series based on DHD : DHD2.5N, DHD3.5N, DHD340N, DHD350N, DHD360N, DHD380N.

QL-N series, improved series based on QL : QL50N, QL60N, QL80N.

In these hammers, the smaller lower end of the piston interacts with a guide sleeve, taking on the role of the foot valve. Unlike the DTH hammers with a foot valve, these have a longer piston and a more compact air distribution system, resulting in a shorter piston stroke, faster impact frequency, and less force per impact. Therefore, non- foot valve DTH hammers are more suited to soft or medium soft rock formation .

Additional advantages of DTH hammers for DTH bits without foot valve include:

1.   High drilling speeds, the drilling speed is 15%-30% higher than the one with foot valve.

2.   Out of issues due to foot valve breakage, damage, and thermal expansion and contraction.

3.   Lower air Consumption, reduced fuel consumption: over 10% savings compared to DTH hammers with foot valves.

4.   Simpler internal structure, lower overall failure rate, less frequent dismantling, reduced downtime for clients.

Clients should choose the most suitable DTH product series based on the rock conditions they need to drill, and can also consult the Sinodrills sales team in advance.

We not only provide reliable products, but also offer professional guidance and suggestions!

There are three methods for inserting carbide buttons: copper brazing, cold press, and hot press.

1. Copper Brazing:

Copper brazing is the earliest way of inserting carbide buttons, primarily determining the size of the hole and the carbide button based on the gap during brazing. According to the bit skirt structure, corresponding button holes are drilled into the bit skirt, and then the carbide buttons are welded into the bit skirt using copper or silver welding techniques.

This method does not require high precision for the drilling or button size. During brazing, the brazing material is placed at the bottom of the carbide button, with some flux sprinkled on the carbide button surface. The brazing material diffuses fully in an oxygen-free condition, forming a dense, uniform, and full weld. The hole only bears the radial and tangential stresses caused by the condensation shrinkage of the weld, with no axial tensile or compressive stress. Additionally, this layer of brazing material can delay the impact during rock drilling, thus avoiding the disadvantages of interference fit.

However, the high temperatures during welding impose thermal stresses, potentially causing defects and micro-crack propagation in the low cobalt alloy, as well as reduced hardness  (by HRC  0.5-0.8 ) and bending strength (by 8%-20%) of the carbide. The formation of an oxide layer on the surface of the alloy button makes the carbide button prone to fracture.

Currently, this method is mainly used for single used button bits, such as blast furnace tapping bits and anchor bits.

2.  Cold Press V.S Hot Press

Cold press and hot press both utilize interference fit to fix the carbide buttons, and the interference is generally between 0.04mm and 0.08mm. Factors influencing the interference include, but are not limited to:

1. Drill bit skirt material;

2. Heat treatment process of the skirt;

3. Diameter of the carbide buttons;

4. The equipment for inserting carbide buttons into the bit skirt.

Cold press is done at room temperature, without the need to heat the button bit, directly using a hydraulic hammer to press the carbide buttons firmly into the button bit.

This process has a lower production cost but lacks stability.

Improper selection of interference can significantly increase the pressing force, sometimes causing the carbide and the hole to be damaged. Even with appropriate interference, the tangential, axial, and radial stresses experienced by the carbide button under heavy loads can accelerate the expansion of existing defects, leading to premature damage to the carbide buttons.

The overall lifespan of cold pressed button bits is limited, particularly in the late drilling stage of button bits, and issues such as buttons popping out or breakage are common.

Cold pressed button bit is generally used for softer, less abrasive rock formation, and higher-end anchor bits often utilize this method.

Unlike cold press, the hot press process takes advantage of the principle of thermal expansion and contraction. It involves heating the bit skirt to a certain temperature, typically between 200°C and 500°C, to expand the diameter of the button holes. Then, the carbide button is inserted into the hole and physically contracted to tightly integrate the buttons with the bit skirt.

This method does not necessitate pressure, or only minimal pressure, thereby avoiding or reducing the impact on the performance of the carbide buttons, making it more effective in maintaining the original properties of the carbide buttons.

Hot press is currently the best and mainstream method for inserting carbide buttons. Hot pressed button bits have better wear resistance, higher hardness, and superior stability, suitable for very hard and highly abrasive rock formation.

As the leading exporter of rock drilling tools in China, Sinodrills’ threaded button bits and down-the-hole button bits are all hot pressed, offering long service life, greater wear resistance, and excellent stability!

There are three methods for inserting carbide buttons: copper brazing, cold press, and hot press.

1.Copper Brazing:

Copper brazing is the earliest way of inserting carbide buttons, primarily determining the size of the hole and the carbide button based on the gap during brazing. According to the bit skirt structure, corresponding button holes are drilled into the bit skirt, and then the carbide buttons are welded into the bit skirt using copper or silver welding techniques. 

This method does not require high precision for the drilling or button size. During brazing, the brazing material is placed at the bottom of the carbide button, with some flux sprinkled on the carbide button surface. The brazing material diffuses fully in an oxygen-free condition, forming a dense, uniform, and full weld. The hole only bears the radial and tangential stresses caused by the condensation shrinkage of the weld, with no axial tensile or compressive stress. Additionally, this layer of brazing material can delay the impact during rock drilling, thus avoiding the disadvantages of interference fit. 

However, the high temperatures during welding impose thermal stresses, potentially causing defects and micro-crack propagation in the low cobalt alloy, as well as reduced hardness  (by HRC  0.5-0.8 ) and bending strength (by 8%-20%) of the carbide. The formation of an oxide layer on the surface of the alloy button makes the carbide button prone to fracture. 

Currently, this method is mainly used for single used button bits, such as blast furnace tapping bits and anchor bits.

2.  Cold Press V.S Hot Press

Cold press and hot press both utilize interference fit to fix the carbide buttons, and the interference is generally between 0.04mm and 0.08mm. Factors influencing the interference include, but are not limited to: 

1. Drill bit skirt material; 

2. Heat treatment process of the skirt; 

3. Diameter of the carbide buttons; 

4. The equipment for inserting carbide buttons into the bit skirt. 

Cold press is done at room temperature, without the need to heat the button bit, directly using a hydraulic hammer to press the carbide buttons firmly into the button bit. 

This process has a lower production cost but lacks stability.

Improper selection of interference can significantly increase the pressing force, sometimes causing the carbide and the hole to be damaged. Even with appropriate interference, the tangential, axial, and radial stresses experienced by the carbide button under heavy loads can accelerate the expansion of existing defects, leading to premature damage to the carbide buttons. 

The overall lifespan of cold pressed button bits is limited, particularly in the late drilling stage of button bits, and issues such as buttons popping out or breakage are common. 

Cold pressed button bit is generally used for softer, less abrasive rock formation, and higher-end anchor bits often utilize this method.

Unlike cold press, the hot press process takes advantage of the principle of thermal expansion and contraction. It involves heating the bit skirt to a certain temperature, typically between 200°C and 500°C, to expand the diameter of the button holes. Then, the carbide button is inserted into the hole and physically contracted to tightly integrate the buttons with the bit skirt. 

This method does not necessitate pressure, or only minimal pressure, thereby avoiding or reducing the impact on the performance of the carbide buttons, making it more effective in maintaining the original properties of the carbide buttons.

Hot press is currently the best and mainstream method for inserting carbide buttons. Hot pressed button bits have better wear resistance, higher hardness, and superior stability, suitable for very hard and highly abrasive rock formation.

As the leading exporter of rock drilling tools in China, Sinodrills’ threaded button bits and down-the-hole button bits are all hot pressed, offering long service life, greater wear resistance, and excellent stability!

SINODRILLS attracted the attention of numerous visitors with our brand strength in the rock drilling tools industry, comprehensive product displays, exquisite booth design, and a professional exhibition team. However, the highlight of our participation in this exhibition was the tapered drill bits we independently designed, developed, and manufactured. This innovative product became the center of attention and inquiries from numerous industry professionals.

Throughout the exhibition, we engaged in in-depth discussions and negotiations with many visitors, exploring their needs and challenges. These valuable exchanges opened up new opportunities for cooperation with potential clients. At the same time, we had the pleasure of reuniting with many old friends whose long-term trust and support enriched our exhibition experience.

SINODRILLS is committed to becoming the leading Chinese brand in rock drilling tools exports, providing high-quality rock drilling products, and offering excellent services to global customers. We aim to reduce drilling costs per meter for our clients and work hand in hand with them toward success. We look forward to meeting you again at future exhibitions and exploring potential business collaborations together, as we continue our journey towards success with every customer."

As one of leading Chinese rock drilling suppliers, we will take part in the BAUMA with our latest products. We sincerely invite you to visit our booth No. 136 in Hall E5.

Guizhou Sinodrills has been deeply involved in the Latin American rock drilling tools market for many years and enjoys a high market reputation. Thanks to this, during the entire exhibition, our booth was so crowded. In addition to meeting and communicating with many previous customers with years of cooperation to consolidate the existing partnerships, we have also discovered large amounts of potential customers.

Through Perumin, we have understood the future development direction of the Latin American rock drilling tools market, which brought new opportunities for the company's future development. We will continue to follow the spirit of specialization, quality and innovation to serve all our customers, and occupy the market by virtue of quality and service.

As one of the leading suppliers of rock drilling tools in China, SINODRILLS will participate in this exhibition with the latest products. We hereby genuinely invite you, as well as representatives of your company, to visit our booth at Booth 788, 789 in Hall C. We sincerely look forward to meeting you at our booth.

Europe is one of the core markets for our company. In this region, we have maintained a stable market for a long time, which is growing year by year. In addition to the influence of BAUMA, we have met with partners from over 40 countries around the world. Meanwhile, we have also had effective communication with several potential customers. Due to the successful cases we have achieved in the past and the excellent market reputation, many potential customers showed great interests in our products, what’s more, there are customers signing purchase contracts with our company on site.

2019 BAUMA fully reflects the recovery of the global construction machinery market, including the demand for our drilling tools. At the same time, we also keenly feel that quality and service are the core competitiveness in the future. Therefore, we will continue to focus on the quality, innovation and service, so as to provide better and more stable products and more superior services for all our customers.

In 2022, let us meet again at BAUMA.

As one of the domestic excellent rock drilling enterprises, Guizhou Sinodrills will take part in the BAUMA with the latest products. We hereby sincerely invite you and your company's representatives to No. 513 booth in Hall C2.

This time, we met our existing customers who have cooperated for many years with us; at the same time also communicated with many potential customers. After the further communication with potential customers, they knew more about our company, in addition, they’ve shown great interests in our self-drilling anchor products and expressed willingness to cooperate with us.

As one of the most important core markets in our company, we maintained a stable market share in Europe for a long time. Combined with the influence of INTERMAT, It gives us great pleasure to meet and communicate with many cooperative partners from France and other European countries. Besides, we also have a professional reception to the potential customers. Some of them not only expressed their willingness to cooperate with us, but also signed a contract with us in our stand. 

The European market as one of the main markets for Guizhou Sinodrills, this time we will carry our products with premium quality to attend the Expo. We genuinely invite you and your company's representatives to No. D058 booth at Hall 5A, with a sincere expectation for meeting you. 

At this expo, our booth has become the focal point of China zone, attracting numerous visitors. We’re honored to meet some of our regular customers and deeply communicate with many potential customers. They’ve shown great interests in our self-drilling anchor (SDA) and DTH drilling tools and expressed keen willingness to cooperate.

MINExpo 2016 will be held from 26th to 28th of September this year with an exhibition area of 76,000 m2, and it will attract more than 1,800 exhibitors from the world.

As one of the excellent rock drilling tool enterprises in China,Guizhou Sinodrills will attend the expo. We look forward to meeting you on 28301 at South Hall.

At this BAUMA, we not only meet and communicate with more than 60 old customers, but also talk with more than one hundred potential customers. Our sales consultants introduce our products patiently and professionally, and many potential customers express their keen interests and strong willingness to cooperate. Some of them even place orders on the spot.

BAUMA 2016 has been over. We’re expecting to meet you again in 2019 in Germany.

The 31st Edition of the World's Leading Trade Fair bauma takes place in Munich from April 11–17, 2016. Once again, the 2013 exhibition set several new records—confirming yet again its leading role as the largest trade fair in the world.

We will be present with our up-to-date products and latest catalogues at BAUMA from 11-17, April, 2016.

Our booth number is c2.505. We look forward to seeing you there, and prepare some small gifts for you.

Our Booth

This is our first time to INTERMAT. Because Europe is always our principal market, and Paris enjoys a unique geographical advantage, we’ve met and discussed with over 30 long-term cooperative customers and distributors from 15 countries during the event. We feel greatly honored. It not only makes us clearly know our customers’ needs, but also lays a solid foundation for providing better products and service in the future.

Talking with our business partners

Introducing our products to the customers

Although the global drilling market is in a downturn, our products still hold a stable market share in Europe by virtue of superior quality, competitive price and better service. Thanks to INTERMAT, We are able to present our products, expertise and service to more potential customers. We’re looking forward to attending INTERMAT in beautiful Paris in 2018.

INTERMAT is organized by S.E. INTERMAT, an umbrella organization bringing together the trade associations for manufacturers and importers CISMA (Association of Equipment Manufacturers for Construction, Infrastructure, Steel and Handling Equipment Industries), SEIMAT (Association of International Civil Engineering, Mining, Construction and Hoisting Equipment Industries) and Comexposium, one of Europe’s leading event organizers.

INTERMAT held every three years in Paris, the show is the global meeting place for construction, mining and materials industries. It is a technological showcase for equipment, components, tools and services, and the stage on which all the latest innovations of the sector are unveiled.

We will be present with our up-to-date products and latest catalogues at INTERMAT from 20-25, April, 2015.

Our booth number is B002, Hall 5B. We look forward to seeing you there, and prepare some small gifts for you.

bauma China rock drilling tools trade fair

Despite the downturn in the market and the severe challenges facing the industry, SINODRILLS in BAUMA China 24 square meters show regional still attracted more than 300 visitors from 23 countries and regions.

bauma China rock drilling tools trade fair

New records for SINODRILLS at BAUMA 2014:

39 old customers visited us

Our booth attracted more than 200 potential customers

More than one million USD orders had been concluded;

bauma China rock drilling tools trade fair

At BAUMA, we had a very nice and fruitful presentation, during four days exhibition, more than 30 old customers visited us and our booth attracted more than 200 potential customers. What’s more, more than one million USD orders had been concluded.

The last event broke all records: With 2,718 exhibitors from 38 countries, 177,080 visitors from 141 countries, and 300,000 square meters of exhibition space, bauma China delivered impressive proof of its status as the biggest and most important sector event in Asia.

bauma China rock drilling tools trade fair

We hereby sincerely invite you and your company representatives to visit our booth at Shanghai, China. We treasure every opportunity to meet with you at hall W2-474

Thanks for good reputation that we had biult over past ten years and as one of leading manufacturers and exporters in China, we had been invited to do an interview by a local TV Station. During the interviewing, our staff introduced SINODRILLS’ business in Chile and Latin America, also expressed the confidence in expanding Chilean and Latin America markets.

EXPOMIN is recognized as one of the world's most important mining exhibitions and is a key industry event for mining in Latin America. The organizers of EXPOMIN 2014 expect there will be 80,000 visitors and 1,400 exhibitors from over 30 countries. This creates a strong opportunity to meet mining executives, specialized distributors and potential commercial partners and customers from Chile and the Latin American region.

SINODRILLS will attend this exhibition from 21 - 25 April. We will bring our newest product catalogues and products attend this fair. We will take products including Rock tools with bits, rods and shanks, and ground drilling tools, with DTH Bit. Also some other related products will be displayed on it.

We hereby sincerely invite you and your company representatives to visit our booth at Santiago, Chile. We treasure every opportunity to meet with you in No.144, Hall 1B

For this equity incentive project, Sinodrills has introduced a scientific and comprehensive "1-3-2" virtual share to registered share conversion plan. This plan entitles the incentive recipients to enjoy on-the-job dividends in the first year, providing immediate rewards. In the following three years, those who pass the rolling assessment will be promoted to be registered shareholders. The equity is distributed based on job contributions, allowing them to share the fruits of the enterprise's growth. The shares after registration will have a two-year lock-up period to escort the company and the talent team to move forward steadily. After the lock-up period expires, equity transactions will not be restricted. This plan not only builds a clear and definite career development path for talents, but also optimizes the company's equity structure and stabilizes the talent team.

This move demonstrates Sinodrills' profound understanding and high attention to the value of talents, and is the concrete practice of its comprehensive upgrade of the talent strategy. Looking forward to the future, Sinodrills will continue to adhere to the "people-oriented" principle, continuously optimize the incentive policy, provide a stage for every aspiring individual to realize higher value, join hands to create a more splendid and glorious tomorrow, and contribute to the development of the industry.

In today's global market, intellectual property has become a crucial part of a company's core competitiveness. We have always placed great importance on protecting our brand's intellectual property. Over the past 20 years, we have continuously improved our company's competitiveness and brand image. As our market share abroad has steadily increased, the "SINODRILLS" brand has become the preferred choice for more and more overseas customers.

Moving forward, we will continue to unlock our brand's potential, pursue ongoing independent innovation, and strive to provide better products and services to our customers, enhancing brand value through product quality.

In creating this modern office environment, we paid attention to every detail: from spatial layout to color schemes, everything has been carefully designed and considered. Our goal was to create a workspace that not only inspires creativity and enhances efficiency but also makes our clients feel welcomed. The new office space has achieved numerous innovations and optimizations to better meet the evolving needs of our business. We have added multifunctional areas such as an open-plan office area, advanced multimedia conference rooms, a global standard international video conference room, an engaging product showroom, and a multifunctional relaxation area. Each of these areas is designed to provide an exceptional work and experience environment.

With this series of upgrades, we aim to improve the comfort and functionality of our work environment to better support our business development and provide excellent customer service. We firmly believe that only in a comfortable and motivating office environment can our employees' potential be fully unleashed, enabling them to provide more professional and efficient services.

We sincerely invite you to visit our new office space. Your visit will greatly encourage our team and propel us forward. We also want to express our gratitude for your continued trust and support. We look forward to creating a brighter future together in our new environment.

SINODRILLS has prepared carefully selected gifts for all female employees and the female relatives of all our staff, with the hope that everyone can enjoy happiness and joy, and also to feel our support and appreciation.

We want to thank all female employees of SINODRILLS. Your professionalism, courage, and dedication make us immensely proud. We also express gratitude to the female relatives of all staff member for their silent support, which enables us to focus on our work.

Finally, we wish all female employees and female relatives of our staff a happy Women's Day!

At the annual meeting, the general manager of SINODRILLS made a comprehensive summary of the company's annual operation, affirmed the work achievements of all departments, and expressed heartfelt thanks to all employees for their hard work. In 2022, all SINODRILLERS faced up to the challenges and rose to the occasion in the face of adversity, and the company achieved brilliant sales results, setting a new high sales performance in the company's history. At the same time, the company also made a qualitative leap in operation and management. Looking into the future, we will continue to work together to write a new chapter of SINODRILLS. At the dinner after the meeting, all SINODRILLERS gathered together and raised a glass to a better future!

"A hundred boats are competing for water, and the one who strives for water is the first." SINODRILLS will continue to take value creation as its mission and high-quality development as its theme and cooperate with all customers sincerely to make steady progress towards the new goal in 2023!

At the meeting, the General Manager summarized the whole year work of the Company and formulated the development direction for the new year. Looking back over the past year, Sinodrills has made extraordinary achievements in its adversity, not only having the sales performance reached a new high, but also continuously improving its operation and management efficiency; while looking forward to the future, it will not forget its original intentions but forge ahead. At the meeting, the General Manager also commended and rewarded the outstanding individuals as selected in 2021, and called on all employees to learn them and make new contributions to the development of the Company. During the dinner after the party, all staff toasted for the future amidst laughter!

2022 is the 20th year of Sinodrills, the struggle of its staff in the past 20 years has laid the foundation for its current outcome, and the customer support for twenty years has contributed to its remarkable achievements. Looking ahead, we are full of confidence, and will continue to work hard to continuously improve our quality and service so as to offer more customers with better, more economical and more efficient solutions to drilling tools.

The new multi-functional showroom has a total area of nearly 150 square meters, including a company introduction area, product showing area, business meeting area and video conference area. Through a variety of exhibition forms such as videos, pictures, physical samples, and interactive touch screens, the company image and products can be showed in an all-round way.

As one of features, the video conference adopts the latest HD video technology and cloud computing technology, it can not only ensure the smooth "one-to-one, one-to-many and many-to-many" video conference with customers all over the world, but also realize function for screen and file sharing during the video conference. It greatly improves the efficiency of video conference. Combined with our wide range of samples, we are able to communicate with global customers efficiently and provide our customers with better pre-sales, in-sales and after-sales services.

The new showroom not only provides a platform for the company to display its corporate image, but also lays a base for us to better communicate and serve with customers. We will also use this as a basis to provide better products and services to more domestic or oversea customers.

Upon hearing the news, our company immediately contacted the local Red Cross and donated RMB30,000.00. Drops of water make up the sea, every penny gathers into hope. We do our small part to support the anti-disaster work. Unite as one to get through the difficulty and fight the disaster through thick and thin. We sincerely hope that the disaster will be relieved at an early date and the local people will resume work and normal routine very soon.

Women are an indispensable force not only for family but also for career. They pay the most powerful and sweet dedication to their family. On the other hand, they give the most meticulous and efficient contribution to their career. Every mother is the greatest person of human society progress, and every woman is a catalyst for the progress of our career. The roles that women play in society are varied and indispensable. Just like flowers blooming in the warm spring, women are also showing their unique charm in their respective fields. We hereby express our thanks to every women for their contribution and dedication, and wish all women a happy holiday!

We will continuously optimize and improve our quality management and service to provide customers with better products and service.

As of late June, 2020, our company has offered more than 60,000 masks to clients located in over 40 countries and areas. The Chinese often say, “Distance cannot separate true friends who remain close even when thousands of miles apart.” SINODRILLS has kept close communications with our all cooperative partners with care and mutual support. We have established deep friendship surpassing the field of trades. We are willing to provide support within our power to all cooperative partners for solidarity against the pandemic.

Glutinous rice dumpling full of affection implies the culture of love and warm wishes for this festival. It seems a simple gift, but shows company’s best wishes to all staff and their families. Wish all staff a good festival and happiness for the whole family.

SINODRILLS will continue to adhere to the operating principle of “Co-innovation, Mutual Sharing” to strengthen our efforts to create more healthy and harmonious family.

Working together to safeguard our safety. We believe that under strong leadership of CPC and the whole state, we will be able to win the battle against the disease through joint efforts taken by all sectors of the society.

The success of being one of key contacting enterprise not only embodies the recognition of our company’s operating achievements over the past years by relative authorities, but also represents our continuous development. As one of the key contacting enterprises we enjoy the priority to receive project support, export tax refund, customs clearance convenience, foreign exchange receiving and financial support provided by government departments at different levels. Our company will take that as our opportunity to continuously adhere to developing based on high quality, good services and credit, in order to provide products with better quality and services to more worldwide customers through constantly strengthening quality management and sense of services.

In the future, SINODRILLS will strictly implement the requirements of quality management system and product quality control, continuously improve our management level, continue to improve our product performance, and provide customers with better products and services

SINODRILLS’ new uniform uses bright red as the main color, which symbolizes the positive working attitude and indomitable spirit of hard work of all SINODRILLERS. It also keeps alerting everyone at all times, maintain strict working conditions at all times, highlighting new achievements for the company's new journey of professional development.

Lugu Lake is like a pearl inlaid in the embrace of the mountains. On sunny days, blue sky and white clouds are reflected in the lake, with the water and the sky merging in one color, which constitutes wonderful sceneries. Due to the beautiful natural scenery and peculiar ethnic customs, the place is called "God Residence" by the explorer Joseph Charles Francis Rock.

During the four days and three nights, everyone was indulged in the landscape, not only experienced the beautiful scenery, enjoyed the joy and relaxation of tourism, but also enhanced mutual understanding, comprehending and friendship. We believe that this short break will inspire us to dedicate ourselves to the work of the second half of the year in a more active and full-fledged state, and constantly break through and create higher performance.

The new-generation “GSE Fully-carburized Taper Drill Rod”, on the original basis, has increased the surface hardness of the rod body sharply and promoted the abrasive resistance of the product. This means that the drill rod not only bears stricter drilling requirements but also lowers down the drilling cost. With the excellent quality and overlong service life, GSE Fully-carburized Taper Drill Rod will provide higher performance and productivity to your drilling work.

GSE Fully-carburized Taper Drill Rod’s advantages:

• The service life extension has leveled up the overall work efficiency

• The abrasive resistance promotion has lowered down the overall drilling cost

• The specification diversification has leveled up the product matching attribute

Guizhou Sinodrills has devoted itself to build up an enterprise that the employee would feel proud of, happy and belonging. On the occasion of such a festival, we’re offering such a present to you. On the occasion of Dragon Boat Festival, we’re sending the best wishes to every employee. The fragrant sticky rice inside the reed leaves not only makes people sense the festival atmosphere but also delivers the appreciations and feelings of the company to every employee.

Guizhou Sinodrills will continue to persist in the operation principle of “Create Together, Share Together” and create a healthy and harmonious Sinodrills family.

We not only arranges basic health examination, blood examination, occupational disease examination and other routine items, but also arranges several specific physical examination items for employees in accordance with the actual situation of the company this year. The annual physical examination is designed to enable every SINODRILLS staff to keep abreast of his or her health, to enhance his or her health awareness, and to share the achievements achieved by the company with all SINODRILLS staff.

Guizhou SINODRILLS will continue to put the care for employees into practice, adhere to the business philosophy with "common creation, and common sharing" so as to create a healthy and harmonious SINODRILLS family.

The trip destination was Dali, a famous tourist resort in Yunnan province. There are four wonders to represent Dali, shortened as” Xiaguan’s wind”, “Shangguan’s flowers”, “Cangshan Mountain’s snow “and “Erhai Lake’s moon reflection”. In Dali, Mt. Cangshan sits above Lake Erhai where the green is mirrored by the blue. Benefiting from such a unique astonishing natural landscape, it is also well known as “ Oriental Gevena”.

We cruised in Lake Erhai and hiked on Mt. Cangshan. We enjoyed beautiful scenery in daytime and tasted delicious food at night. The three days’ tour not only relieved us from work pressure, but also built up our team cohesion. More significantly it inspired all of us to devote more enthusiasm into our work in the second half year with a motivation to achieve a greater glory.

Since the company has been established, we know that integrity is the foundation of an enterprise. We have won this honor again, which means the full recognition of the governmental authorities for our consistent integrity management. It not only shows the corporate image of our company, but also constantly reminds us that we need to pay high sense of responsibility to provide better products and services to the customers.

Acquiring this certificate proves the full recognition of China customs for our standardized management and honest operation, which enables us to enjoy more convenient clearance process in our export business. We will take this opportunity to strengthen our management in the hope of providing more efficient and professional service to our customers.

SINODRILLS’ new uniform pays attention to practicality and beauty. Every employee shows their professional through the uniform, also reflected all staff spiritual outlook, and strengthened the centripetal force and cohesion for all SINODRILLER. At the same time, it also improves the public image of the company. The uniform shows the standard and specification of the company, and deliveries brand image to everyone.

Jiuzhaigou valley, as one of the most famous World Natural Heritage, it's the first nature reserve of China which is established for the main purpose of protecting the natural landscapes. The alpine lakes, spectacular waterfalls, color forest, snow-capped mountains, blue Ice, and Tibetan folkways are called "six absolutely of Jiuzhaigou". It is known as the "Fairy Tale World" and "King of Water view".

The scenery along the way makes us relaxed and happy, and also enhances the interaction and communication of each other. During these five days of travel, we not only show a harmonious, enjoyable and vigorous team spirit, but also strengthen condense force and inject more energy into the works of the second half of year.

In this field we’ve made huge progress from scratch, just like the development of Sinodrills, from a trading company 14 years ago to a professional drilling tool supplier with production, sales and service today. With the spirit of "Drilling more, drilling globally", we will spare no efforts to forge ahead and provide our customers with better products and excellent service.

Yellow is a color full of vitality and hope, just as Sinodrills, a promising company. Yellow is also a symbol of wealth, and we hope all our customers create more wealth along with us. Yellow can also warn people, and reminds all Sinodrillers to seriously treat our customers and products.

Since the establishment, Sinodrills firmly sticks to uncompromising integrity as the foundation of business operation and one of the most essential principles for development. Gaining the title not only recognizes our achievement in contract fulfillment and enterprise credit construction, but also reminds us to treat our customers, employees, and cooperative partners with integrity.

The rating of 3AA2 reflects a company’s ability to fulfill contract, comprehensive credit, strength and competiveness. It not only honors us, but also urges us to do better. With sound corporate reputation, quality products and excellent services, we will grow bigger and stronger along with our partners and customers in rock drilling industry in the future.

It’s the second time to increase our registered capital since the establishment of the company, showing our company steps into a new development stage. The addition not only enriches our operating capital and improves our market competiveness, but also affirms our business performance during these years and shows our customers confidence. Based on this, we will continue to improve ourselves and modify our products, commit ourselves to rock drilling industry, and try to become the most reliable rock drilling supplier in China.

Chishui City, located in the farthest northwestern part of Guizhou with a forest coverage rate of 80.3%, is the only national scenic site named after an administrative region by The State Council. The city enjoys good reputations as “City of a Thousand Waterfalls”, “Hometown of Nan Bamboos”, and “Kingdom of Spinulose Tree Ferns”. The legend of Chinese Red Army Crossing Chishui River Four Times and The list of Chishui Danxia as World Natural Heritage make it more famous around the world.

During the three-day trip, we relax our heart and soul in the nature; we help each other and care for each other; we get physical and mental pleasure and enhanced harmony, solidarity and cooperation, which not only strengthen our team cohesion, but also inject tremendous energy to our work in next half of the year.

Returning from Chishui, we are all pouring full passion and enormous energy into our work. We believe that all Sinodrillers will continuously provide superior products and better service to our customers in the future.

After more than two years process of modification and repeated tests, we now successfully develop a new kind of tapered button bits. Our new tapered button bits are featured with all new processing technology, unique steels of bit skirts and excellent quality of carbides.

During the past two years testing under various geological conditions in more than 10 countries, our new taper button bits show both performance and average life span are comparable with international leading brands, such as Sandvik or Atlas Copco, however, our price is lower by at least 30%, even 50%

In order to clearly show our products to our customers in a more professional way, SINODRILLS had thoroughly upgraded all the existing product catalogues by the end of 2014. The latest version can give you a more specialized and specific description and introduction on our products. We adopt a brief style during the page editing so that our customers can easily search the products they need. From designing to typesetting, all the catalogues are composed according to our company VI and have achieved a high unification. No matter their appearance or the inside pages can be presented to our customers in a clear and simple way.

The current updated catalogues are including General Catalogue, Self-drilling Anchor Catalogue, DTH Bit Catalogue, DTH Pipe Catalogue, DTH Casing Drilling System Catalogue and DTH Hammer Catalogue. Next we are going to update our other products catalogues, including Top Hammer Drilling Tools Catalogue, Drag Bits Catalogue and Diamond Exploration Drilling Tools Catalogue.

BEC Vantage, as one of our regular trainings, is carried out among our First business department, Second department and Marketing department. The training is aimed to improve all business personnel’s ability of English speaking, writing and listening.

sinodrills' training With continuous improvement and enhancement, we believe that we all SINODRILLERs can serve every valued customer better and better.

Thanks for our reliable quality, competitive prices and professional services, “Made by SINODRILLS” has been exported to 82 countries and areas in the world and been accepted and chosen by more and more drillers, contractors and distributors.

Through twelve years development, we have been continually growing stronger. In order to meet the company development, we now launch a new Logo as shown below:

SINODRILLS' NEW LOGO

The new Logo is composed of blue and yellow. The former represents a positive and exuberant vitality, which symbolizes our positive attitude, tenacious and courageously struggle spirit toward work; the latter stands for we are dealing in the Rock Drilling field and will constantly offer the best quality and services to consumers. With an opened circle in the middle means we will adhere to making all better; the highlighted yellow triangle guides us forward. We will endeavor to be a top supplier in Rock Drilling Tools Industry in China by continuously improving to provide better and better products and service.

Therefore, we would like to draw your attention and look forward to your continued support and cooperation.

                                                                                View of Guliangyu, Xiamen

Four days trip was short but full, everyone had a good time and was fully relaxed both in body and mind during those days, and closed the relationship among employees and created a united and positive environment at the same time, which greatly enhancing the cohesion and solidarity of our sales team. We always believed that this kind of activities is not only in recognition of what we have done in the first half of the year but also a new start of our next success.

                                                                                Sales team of SINODRILLS

At last, we would like to express our sincere gratitude to all of our clients from more than 80 countries in the world for your trust and support,meanwhile please believe we all SINODRILLERS will do our utmost to offer more and better products and service in future.

CE marking indicates the compliance with EU legislation of a product, wherever in the world manufactured, and enables its free movement within the European market. By affixing the CE marking on a product, a manufacturer is declaring, at its sole responsibility, conformity with all of the legal requirements to achieve CE marking which allows free movement and sale of the product throughout the European Economic Area.

After many strict tests had been passed in UK, SINODRILLS Self-drilling anchoring tools were certified with CE  in May, 2014. The CE certificate covers our full range of Self-drilling rock bolts including R25, R32, R38, R51, T76, T30, T40, T52, T73, T103, T111, T127 and T130.

Date: In January, 2014.

DTH Drill Rig Model: DM45 HP & DML

DTH Hammer Model: SINODRILLS QL60 quick hammer

Rock Formation: Rock conditions vary widely, from mild rock (not very abrasive) to very hard and very abrasive.

DTH Button Bits Configurations: QL60 171mm, 10 gauge buttons x 18mm, 10 face buttons x 18mm, two flushing holes

                                                      New bits                                                                       After 18 times sharpening

Our three pieces of QL60 171mm button bits had been tested from the 7th to 20th of January, as below, it was the summary for the drilling test.

As below, it was our # 1 bit detailed drilling record from the site.

Remarks: Red box: with SINODRILLS brand QL60 quick hammer, 0.68 m/Min average speed;

Yellow box: with world famous brand A QL60 shank hammer, 0.55 m/Min average speed.

As below, it was the summary from the site manager about SINODRILLS DTH button bits:

SDA system may be used for different rock conditions, and drill bits are available in different designs and diameters. The thread types are compatible to international standards and can easily be adapted to standard rock drilling equipment. The SDA range is available in different load capacity classes, depending on the outer and inner diameter of the bar.

The self-drilling anchor bolt system makes your anchoring much easier, as it is capable of performing procedures of drilling, anchoring and injection all at once.

Self-drilling installation may be accomplished either manually or semi-automated, depending on the available drilling machinery.

Main Advantages of Self Drilling Anchor system

• Simultaneous drilling and installation

• Installation using standard drilling machinery

• Immediate load-bearing capacity after installation and activation of the expansion element

• Reduction of cycle time due to the de-coupling of the grouting procedure from installation

• Ability to maintain load-bearing capacity even when undergoing large deformations

• Tough system components

• Safe, easy, and reproducible installation procedure

• Improved drilling accuracy thanks to the directional guidance of the self-drilling expansion element

• Trouble-free application in unstable borehole conditions

• Easy extension using couplings

• Design and diameter of the expansion element can be adjusted to suit different and varying ground conditions

SINODRILLS Self Drilling Anchor System may be used as a fore-poling element for pre-support or as a lance for injection works.

Fields of Application

• Civil Engineering

• Underground Mining and Tunneling

Typically installed with rotary percussion drilling, using the simultaneous drill and grout technique where grout is pumped through the bore of the bar to the sacrificial drill bit as drilling is advanced with the grout flush comprising a part injection / part flush system. Permeation of grout beyond the nominal borehole diameter can occur in granular soils but be very limited or non-existent in cohesive soils. Air flush, with very careful flush control, has been used in cohesive soil;

May be constructed with cased or un-cased drilling systems to form the borehole into which the anchor components (either bar or strand) are inserted and grouted in place;

Have a defined free length which is isolated from the ground and is free to extend elastically when the anchor is stressed and then throughout its working life;

During the construction of underground works, it is very common to encounter soft rock, fractured zone and large deformation due to high ground stress. In the case of serious collapsing, extra-long anchor is needed instead of ordinary one.

Based on these reasons, IBO self-drilling anchor drilling tools are more and more widely used in underground, support, tunnel and other fields.

IBO Self-drilling anchor embodies drilling, grouting and anchoring as a whole. It widely used as an efficient anchoring means, in tunnel pre-support, slope, coast, mine, water conservancy projects, building foundation, roadbed reinforcement and geological diseases treatment such as landslip, crack, sink age. It’s irreplaceable in narrow construction environment.

The IBO self drilling anchor bolts are fully threaded, hollow core, cold rolled anchors with continuous outside thread suitable for attaching bits and couplings, which also forms a superb mortar connection. They are supplied with couplings, anchor plates and nuts, and anchor drill bit.

IBO Self Drilling Anchors are used for temporary and permanent stabilization; retaining walls in confined spaces; and slope stabilization for roads, railways, and tunnel portals. Whether used in cohesive or non-cohesive ground, the IBO self drilling anchor can be grouted and then stressed and locked off with nut and plate. Advantages are: similar installation for all ground conditions; no casing required; fast drilling and anchoring in a single operation; choice of bits and anchor loads; and hollow core for high-volume flushing and grouting.

Features of IBO self drilling anchor system:

1, High penetrability anchor drill bits, they are very easy to penetrate various rocks.

2,  Self-drilling anchor can be used at the place with narrow space. With continuous thread, achieving the aim of rock reinforcement with extra-long anchor

3, Unnecessary to be pulled out. Hollow steel can be used as grouting channel;

4, Embodies drilling, grouting and anchoring in one step.

The entire self drilling anchor system is mainly composed of the following important parts:

Self drilling anchor bolt/bar (SDA / IBO)

Self-drilling anchor bolt is a fully threaded hollow steel rod, it manufactured from high quality steel, with cold rolled to standard thread. The hollow core used for flushing, drilling and grouting.

The self drilling anchor bolt has more bending strength for reinforcing solid bars, soil nails, and rock anchors.

Self drilling anchor bit

The drill bit used to drilling, and help self drilling anchor bolt insert the hole at the same time. According to different geological conditions, it can be chosen with different shapes and materials.

Self drilling anchor coupler

The main purpose for coupler is to connect the self drilling anchor bolts. It used to extend the self-drilling hollow bars. Self-drilling anchor couplings are used to link anchor bars to make the anchor longer, thus promote its installation depth.

Self drilling anchor nut

Self-drilling Anchor nut is used to lock the anchor system. It manufactured from high precision steel with chamfered edges on both ends from high precision steel, and tempered to meet the stringent demands on anchor specifications and the daily operations of underground work.

Self drilling anchor plate

The plates feature a chamfered bore to ensure firm seating of the nut. The self-drilling anchor plate transmits load force from the self-drilling anchor system to the work face.

Other Accessories

Applications of Self-Drilling Anchors

Slope stabilization	Foundations with micropiles	Tunneling & Mining

The Self-drilling hollow anchor bolt is a fully threaded hollow bar which can be simultaneously drilled and grouted into loose or collapsing soils and brittle rock without the need for a casing.

The rock bolt is connected to the hydraulic rock drill by an adapter device and installed in the way a conventional borehole is drilled. There is a hollow interior of the self-drilling anchor bolt, a threaded exterior and a drill bit that is used for drilling. The self-drilling anchor bolt’s hollow interior enables air and water to freely more though the drilling process, flushing the particles. After completion of the drilling process, it also enables immediate injection. Continuous thread enhances pull-out resistance with grout. For fractured or hard rock formations as well as uneven ground conditions (such as gravel, soft, clay and non-homogeneous soil), self drilling anchor bolts present a specific bolting solution.

The self-drilling anchor bolt system makes your anchoring much easier, as it is capable of performing procedures of drilling, anchoring and injection all at once.

SDA system may be used for different rock conditions, and drill bits are available in different designs and diameters. The thread types are compatible to international standards and can easily be adapted to standard rock drilling equipment. The SDA range is available in different load capacity classes, depending on the outer and inner diameter of the bar.

Self-drilling hollow anchor bolt is mainly used in slope stabilization, tunneling pre-support, foundations with micro piles, it is also widely used in the railway system, metro project etc. It can be installed in sites with weak rocks, loose soil, and weathered layer, sand with stone layer and so difficult to create a hole in complex formations. The unconsolidated ground condition favor the self-drilling anchor bolt technique for fast and simple method of installation compared to the traditional method.

The hot-dipped galvanized coating is excellent for use in moist atmospheres where more rust resistance is required than the standard zinc plated wedge anchors can provide.  Ensure the service life of the anchor rod.

Hot-dip galvanized self-drilling anchor bolt

Galvanized self-drilling anchor system / full threaded steel self-drilling rock bolt / hollow anchor bar / anchor rods.

In order to reduce the corrosion rate and thus increasing the service life, SINODRILLS offer hot-dip galvanized systems. A complete hot-dip galvanized system is usually including hollow bar, coupler, nut and plate. All hot-dip galvanized items confirm to following standards:

SINODRILLS Galvanized Self drilling anchor bolt Parameters for T Thread

SINODRILLS Galvanized Self drilling anchor bolt Parameters for R Thread

Application of SDA (Self Drilling Anchoring system)

Self drilling anchor system can be used for underground applications and in civil engineering. In the field of underground applications, it can be used for bolting, piling, face stabilization, as fore poling element for pre-support, or as a lance for injection works.

The Self drilling anchor System also features a wide range of applications in civil engineering such as rock and soil nails, micro-piles, or ground anchors. The system is an “all in one” tool for drilling, flushing, post- or simultaneous grouting, and finally the load-carrying member itself.

Installations in weak ground and unstable borehole conditions represent no difficulty and are ideal for the application of the Self drilling anchor system.

Main Constitution of SDA (Self Drilling Anchor system)

01  Anchor Bit	02  Anchor Bar	03 Anchor Coupler	04 Anchor Plate	05 Anchor Nut

• Self drilling anchor bar (Hollow anchor bar)

Hollow anchor bar is the body of a self-drilling anchor, as a hollow steel tube with an outer round thread, hollow anchor has the sacrificial anchor bit connected at one side, plate and nut connected at the other; two hollow anchor bars could be connected together via a coupling, for duties that requiring longer anchors.

• Self drilling anchor bits

Anchor bit is the front part of the self-drilling anchor system, by cutting and drilling rocks and other geological structures, the anchor could be sent to the designed depth.

• Self drilling anchor coupler

Self drilling anchor couplings are used to link anchor bars to make the anchor longer, thus promote its installation depth. 

• Self drilling anchor plate

The self drilling anchor plate transmits load force from the self-drilling anchor system to the work face.

• Self drilling anchor nuts

Self drilling anchor nut locks the plate, transmits force from anchor bar to plate and finally to the working face.

Soil nailing is an efficient, effective and economical method of soil reinforcement. The reinforcement is installed into the slope face of in-situ ground, whether natural soil or an existing fill, stabilising such material. Soil nailing can be used to stabilise, existing structures such as unstable slopes, embankments and retaining walls. The use of soil nails can be adopted for the stabilisation of cuttings and coastal and quarried cliffs. The construction of new steep slopes for widening of infrastructure routes, new developments and new retaining walls, has seen an increase in the use of soil nailing. This method of soil reinforcement can be used for both permanent and temporary applications.

The self drilling anchor(SDA) system offers self-drilling soil nails where the central hollow threaded reinforcement bar acts as both final reinforcement in the completed anchor and as the drill rod during installation. The self drilling anchor(SDA) system is installed with sacrificial drill bits under a grout flush. In granular deposits in particular, the impregnation of grout into the surrounding ground significantly enhances the geotechnical capacity of the anchor. Large slabs of concrete and rock can also be readily drilled. These anchors work well as both tension and compression tiebacks and can be installed horizontally to meet any tieback or anchoring design criteria.

The application for self drilling anchor soil nailing include the stabilization of enbankments, dams, cuts, unstable slopes and tunnel entrances and the refurbishment of retaining walls.

Range of applications

Slope stabilisation	Anchoring sprayed concrete	Stabilizing existing retaining walls
Dams Cuts Embankments Erosion protection Protective nets Avalanche protection	Excavations Retaining walls Tunnel entrances Emergency stabilization measures	Retaining walls Stone walls Concrete walls Crib walls

SELF DRILLING HOLLOW ANCHOR BOLT

The hollow bar features a left hand or right hand with R thread (rope / round thread) or T thread (trapezoidal thread) for easy extension and connection to all conventional drill rigs. It is manufactured from high quality seamless steel tubes. The R thread and T thread all according to ISO standards or international standards, and both thread formed in a cold rolling process.

COUPLERS

The couplers are used to extend the hollow bars. The required length of the load-bearing element can thus be achieved also in cases of limited feed length of the drill rig or low headroom conditions.

All couplers are designed to safely transfer the specified system load, with the faces of the hollow bars bearing against each other to ensure safe energy transfer between the hollow bars and the drill bit without affecting the couplers mechanically.

PLATES

The steel plates feature a chamfered bore allowing an angle of deviation of 5 degrees in all directions.

NUTS

The nuts transfer the load from the plate into the hollow bar. They feature a spherical cap on at least one end to compensate for angle deviations. All nuts are so designed as to ensure safe transfer of the specified system load.

DRILL BITS

The correct selection of the drill bit dependent on the geological conditions on site is essential to ensuring a productive and cost-effective installation of the Self Drilling System.

Therefore, applied protective methods are directed towards a reduction of the corrosion attack and the respective damages to the reinforcement or ground control elements during their intended lifetime.

Corrosion Protection Methods

The selection of the optimal corrosion protection method(s) depends on the corrosion potential of the environment, and the type as well as the intended service life of the structure.

The load-bearing element, transition zone between borehole and surface, and the head construction must be assessed separately.

Corrosion protection methods are divided into two main groups.

The first one is called active, and comprises all influencing methods which eliminate or reduce the corrosion reaction. A common example for active corrosion protection is encapsulation with concrete.

The second one is called passive corrosion protection, including methods to produce a protective layer on corrosion endangered parts, for example duplex coating systems.

Self-drilling hollow steel bolt tendons for permanent application are reliably protected by surrounding body of cement grout. The following additional measures can be employed to improve the corrosion protection for special applications.

Hot-dip galvanized self-drilling anchor bolt

Galvanized self-drilling anchor system / full threaded steel self-drilling rock bolt / hollow anchor bar / anchor rods.

In order to reduce the corrosion rate and thus increasing the service life, SINODRILLS offer hot-dip galvanized systems. A complete hot-dip galvanized system is usually including hollow bar, coupler, nut and plate. All hot-dip galvanized items confirm to following standards:

Duplex Coating Introduction

According to EN ISO 12944-5, duplex systems are understood to be a corrosion protection system which consists of galvanizing in combination with one or more subsequent coatings.

The corrosion protection working mechanism of duplex systems is based on mutual protection of the partners. Protected by the powder coating, the zinc layer remains intact for an extended time period.

The hollow anchor bar incorporates a thread for standard rotary percussive drilling. Manufactured from high grade steel tubing, and Hollow anchor Bar is cold rolled to form standard Rope thread or “T” thread profiles. The Drill rolling process refines the grain structure of the steel, increasing the yield strength and producing a robust drill steel suitable for a range of drilling and grouting applications.

The Hollow Anchor Bar System includes a full range of drill bits, adaptor sleeves, couplers, nuts and bearing plates.

Key Features

■ Bars can be drilled into loose or collapsing soils without the need for a casing to support the borehole.

■ Continuous thread ensures that rods can be cut and coupled at any point, or extended.

■ Grout is injected at all points of the borehole as drilling is advanced, permeating the local strata for increased bond performance and producing bulbing in softer sections of the soil.

■ The self-drilling function enables bars to be drilled into most ground conditions for both tension or compression applications, and is also used as an injection conduit.

• Uses: Roof and wall bolting as a temporary support in tunnels.

Installation Procedure:

• Drilling, grouting, and anchoring, in one operation. The hollow steel anchor rod also acts as a grouting pipe to ease set up.

Design Considerations and Specifications:

• The ground is a vital element of the ground anchor system; therefore a good quality geotechnical investigation is essential. Various parameters to be considered during geotechnical investigations should include Classification of rocks (Geometry of discontinuities, unit weight, degree of weathering, Index test), Rock stratification, Unconfined compression strength of intact rock, Shear strength and deformability of rock mass, Permeability, Ground water conditions, Corrosion potentials of rock and ground water etc.

• Moreover, the design of the anchor system is based on rock parameters and the geometry of the anchor arrangement. Where changes in the anchor locations, spacing’s or inclinations are proposed, appropriate studies or proving tests should be undertaken to demonstrate the suitability of such an arrangement. The design of the anchor should consider the following-

• Loads and constraints of loading imposed by the anchors on the overall structure

• The way in which the loads will be applied to the anchor during its designed life i.e. static or dynamic

• The load distribution of the anchor arrangement on the structure during stressing and during the design life of the structure

• The interface between the anchor and the structure to ensure structural stability

• The consequence of anchor failure during stressing and thereafter. The diameter and tensile strength of bolt and also arrangement (number, spacing etc.) of rock bolts to be used may vary according to design. The diameter of rock bolts depend on the mass of the rock to be supported by each rock bolt and the force of resisting shear in the bedrock.

• EN 1997-1 – Geotechnical Design-Part 1: General Rules and BS EN 1537-2000- Execution of Special Geotechnical work- Ground Anchors may be followed for all geotechnical designs, installation of Ground Anchors. DIN 1054:2005-01 – Ground verification of the Safety of Earthworks and Foundations IS is also being used for geotechnical designs for ground anchors.

• Generally, Self-drilling Anchors for pipe roofs having minimum diameter 76 mm with a minimum yield load of 1200 kN are used as a temporary support in tunnels.  

• The yield loads of the bolt get transferred through thread to nut, washer, anchor plate and coupling etc. Hence, these should also be designed accordingly. The rolled thread should be in accordance with ISO 10208.

• Manufacturing of Self-drilling Anchors for pipe roof should conform to BS EN-10083- 1 “Steels for quenching and tempering - Part 1: General technical delivery conditions”.

• For all types of Self-drilling Anchors for pipe roof, the anchor head shall be designed in accordance to EN 1537:1999, and should be able to accommodate deformations, which may occur during the design life of the structure.

• Corrosion protection of Self-drilling Anchors for pipe roof should comply with Para 6.9 of EN 1537:1999.

• Tensile test of Self-drilling Anchors for pipe roof should be done in accordance to EN 10002-1. The test involves straining a test piece in tension, generally to fracture, for the purpose of determining one or more of the mechanical properties i.e. percentage elongation, tensile strength, yield strength, upper yield strength etc.

• Impact test of Self-drilling Anchors for pipe roof should be done in accordance to EN 10045-1. The test consists of breaking by one blow from a swinging pendulum, under conditions defined in code above. The energy absorbed is a measure of the impact strength of the material.

Note: All information comes from the Internet, please contact delete if it is inappropriate.

Use: Self-Drilling Rock Bolt is a rock-bolting system based on fully coarse threaded hollow bar. It is especially recommended for the following applications:

•Roof and wall bolting as a temporary support in tunnels.

• All ground conditions. Self-Drilling Rock Bolts do not require pre-drilling a hole, therefore making it usable even in soft rock conditions.

• Self-drilling bolts shall be used in ground conditions where the effective installation of other types of rock bolts is impossible.

• For loose ground/ fractured rock conditions, where drill holes collapses immediately during the drilling, the Self Drilling Anchors can provide immediate stabilization of the opening.

• It shall be grouted through the flushing hole immediately after completion of the drilling operation or simultaneously with the drilling as required.

Installation Procedure:

• Drilling, grouting, and anchoring, in one operation. The hollow steel anchor rod also acts as a grouting pipe to ease set up.

Design Considerations and Specifications:

• The ground is a vital element of the ground anchor system; therefore a good quality geotechnical investigation is essential. Various parameters to be considered during geotechnical investigations should include Classification of rocks (Geometry of discontinuities, unit weight, degree of weathering, Index test), Rock stratification, Unconfined compression strength of intact rock, Shear strength and deformability of rock mass, Permeability, Ground water conditions, Corrosion potentials of rock and ground water etc.

• Moreover, the design of the anchor system is based on rock parameters and the geometry of the anchor arrangement. Where changes in the anchor locations, spacing’s or inclinations are proposed, appropriate studies or proving tests should be undertaken to demonstrate the suitability of such an arrangement.

The design of the anchor should consider the following:

• Loads and constraints of loading imposed by the anchors on the overall structure

• The way in which the loads will be applied to the anchor during its designed life i.e. static or dynamic

• The load distribution of the anchor arrangement on the structure during stressing and during the design life of the structure

• The interface between the anchor and the structure to ensure structural stability

• The consequence of anchor failure during stressing and thereafter. The diameter and tensile strength of bolt and also arrangement (number, spacing etc.) of rock bolts to be used may vary according to design and site requirements. The diameter of rock bolts depend on the mass of the rock to be supported by each rock bolt and the force of resisting shear in the bedrock.

•EN 1997-1 – Geotechnical Design-Part 1: General Rules and BS EN 1537-2000- Execution of Special Geotechnical work- Ground Anchors may be followed for all geotechnical designs, installation of Ground Anchors. DIN 1054:2005-01 – Ground verification of the Safety of Earthworks and Foundations IS is also being used for geotechnical designs for ground anchors.

• Generally, Self-drilling Anchors/bolts having minimum diameter 32 mm with a minimum yield load of 200 kN are used for Rock bolting/ Face bolting as a temporary support in tunnels. 

• Adverse interactions of anchorages should be avoided, by keeping a space not less than 1.5 m between them, if possible.

• The yield loads of the bolt get transferred through thread to nut, washer, anchor plate and coupling etc. Hence, these should also be designed accordingly. The rolled thread should be in accordance with ISO 10208.

• Manufacturing of Self-drilling Anchors should conform to BS EN-10083-1 “Steels for quenching and tempering - Part 1: General technical delivery conditions”.

• For all types of Self-drilling Anchors, the anchor head shall be designed in accordance to EN 1537:1999, and should be able to accommodate deformations, which may occur during the design life of the structure.

• Corrosion protection of Self-drilling Anchors should comply with Para 6.9 of EN 1537:1999 as required.

• Tensile test of Self-drilling Anchors is done in accordance to EN 10002-1. The test involves straining a test piece in tension, generally to fracture, for the purpose of determining one or more of the mechanical properties i.e. percentage elongation, tensile strength, yield strength, upper yield strength etc.

• Impact test of Self-drilling Anchors should be done is done in accordance to EN 10045-1. The test consists of breaking by one blow from a swinging pendulum, under conditions defined in code above. The energy absorbed is a measure of the impact strength of the material.

• Pull out test on Self-drilling Anchors should be performed of on the basis of IS: 11309 – Method for conducting Pull-Out Test on Anchor Bars and Rock Bolts. - Minimum three pull out tests shall be conducted in one rock formation as mentioned in clause 4.8 of IS: 11309-1985 or as per the instructions of Engineer-in-charge.

Note: All information comes from the Internet, please contact delete if it is inappropriate.

The Self drilling anchor tools consist of a drill bit attached to a hollow steel tendon, which is drilled, installed and grouted at the same time, allowing ground improvement, increased productivity and economics.

SDA system is commonly used throughout the civil engineering and tunneling industries. They are used to improve the stability and load bearing characteristics of a rock mass. Within the civil engineering industry, self drilling anchor tools are used for fixing rock netting, slope stabilization, stanchion bases and rock fences. Self drilling anchor tools are also used in structural repairs on retaining walls, bridge spandrel walls and tunnels. In the tunneling industry, SDA systems are used for horizontal fore-poling, slope stabilization at the tunnel portal and for anchoring large section tunnels with high side walls.

      Advantage of Self drilling anchor tools

      • Greater productivity than conventional systems

      • No casing required in collapsing ground conditions

      • Unlimited service life

      • Composed of high yield, low carbon steel

      • Suitable for all ground conditions

      • Can be either passive or stressed

• SDA soil nails R25 to R51N

Soil nailing is a construction method used to maintain or increase the stability of soils by installing reinforcing elements (nails) according to the principles for the execution of geotechnical works. The soil reinforced with nails forms a supporting structure.

The nails are primarily subjected to tensile loads. In addition, bending and shear loads may occur as well. The structure must be so designed that the nailing forms a redundant system. One single nail may not serve as the only load-bearing element.

The principles for the application and execution of soil nail systems are specified in the application standard EN 14490: Soil nailing, and include information on the installation of soil nails, soil investigations, construction materials and products, design criteria and installation aspects as well as testing and surveillance of soil nail production. In addition, requirements regarding surface preparation, drainage and facing are discussed as well.

• SDA rock nails R25 to R51N

Similar in design to soil nails, rock nails serve to stabilize fractured and fissured rock.

• SDA micro-piles R32N to T111N

The piles are suitable to bridge soil layers with low load-bearing capacities and to lay foundations in deep load bearing soils. Tension micro piles are also used to protect against uplift, to activate effective soil as ballast. In narrow spaces, they are used to strengthen existing structures.

Self drilling anchor bolts are commonly used throughout the civil engineering and tunneling industries. They are used to improve the stability and load bearing characteristics of a rock mass.

Within the civil engineering industry, Self drilling anchor bolts are used for fixing rock netting, slope stabilization, stanchion bases and rock fences. Self drilling anchor bolts are also used in structural repairs on retaining walls, bridge spandrel walls and tunnels.

In the tunneling industry, self drilling anchor bolts are used for horizontal fore-poling, slope stabilization at the tunnel portal and for anchoring large section tunnels with high side walls.

The advantages

The advantages of the Self-drilling system are:

       • Variable applications.

       • Especially advantageous in rock/soils with low cohesion.

       • Simple to install in unstable boreholes.

       • No stalling when drilling across clefts.

       • Drilling and installation in one cooperation.

       • Grouting assured over full depth of the borehole.

       • No need to extract drill strings.

The main applications of Self Drilling Anchor Systems in Tunnel Construction

Self-drilling spiles • For stabilization ahead of working face • For safeguarding operations at the working face	Rock bolts • Anchoring system can accommodate rock pressure • Local stabilization of blocks and fault zones • Follow-up rock stabilization	Tunnel face anchors • Stabilization of working face in squeezing rock masses. • Stabilization of working face when using pipe umbrellas	Tunnel floor reinforcement • For strengthening the base of the tunnel arch

Soil nailing is a construction method used to maintain or increase the stability of soils by installing reinforcing elements (nails) according to the principles for the execution of geotechnical works. The soil reinforced with nails forms a supporting structure.

The nails are primarily subjected to tensile loads. In addition, bending and shear loads may occur as well. The structure must be so designed that the nailing forms a redundant system. One single nail may not serve as the only load-bearing element.

The principles for the application and execution of soil nail systems are specified in the application standard EN 14490: Soil nailing, and include information on the installation of soil nails, soil investigations, construction materials and products, design criteria and installation aspects as well as testing and surveillance of soil nail production. In addition, requirements regarding surface preparation, drainage and facing are discussed as well.

• Low-noise percussion drilling.

• No separate system installation, no casing and rod removal required. The drill bit remains in the ground serving as a spacer.

• Choice of drill bits for the most diverse ground conditions.

• Identical installation principle for all ground conditions and systems.

• The hollow core anchor rod serves not only to flush the borehole with air or water during drilling, but also to grout voids and to carry out high-pressure injections of the annular space.

• Choice of high-quality grouts and mixers.

• Flexibility in length by using couplers.

• Ability to work with small drill rigs without casing in narrow spaces.

• Enhanced corrosion protection.

• The high standard of QA systems consistently ensures high quality from production to installation of the injection anchors/piles.

• National and European approvals with CE marking.

• Drill bits of various diameters and types (as suitable for the respective ground).

• Hollow core anchor rods of various diameters with a continuous rolled left-hand thread and available in standard lengths of 1 m, 2 m, 3 m, 4 m and 6 m.

• Couplers to connect and extend the hollow core anchor rods, with center stop for enhanced energy transfer and sealing.

• Solid plates or domed plates for connection to the structure.

• Hexagonal nuts for anchoring and locking.

To ensure thread ability, the thread surface of the accessories may remain un-galvanized. Should small voids become visible on the anchor nut end facing towards the bar, these must be filled with zinc dust paint.

Agt, which is the percentage total elongation at maximum force, is that measure of elongation which excludes that considerable and highly localized extension of the steel under test in the area of plastic instability adjacent to the point of fracture.

Ductility is a measure of the degree of plastic deformation that has been sustained at fracture. A material that experiences very little or no plastic deformation upon fracture is termed brittle. The value of Agt can denote the ductility. For the sake of safety, the minimum number of 5% Agt is required for all Slef Drilling Anchor bars. Sinodrills guarantees minimum 6% in Agt.

Drilling tools are applied in many scenarios in tunnelling engineering, including blasthole drilling, pre-grouting, rock reinforcing, etc. Different scenarios require different features of the drilling tools.

We offer drilling tools for rock drilling, crushing duties and self-drilling anchors for pre-supporting with reasonable price and reliable performance.

Parameters

Size	O.D (mm)	I.D (mm)	Ultimate Load (kN)	Yield Load (kN)	Weight (kg/meter)
T30-11	30.0	11.0	320	260	3.3
T30-14	30.0	14.0	275	220	2.9
T30-16	30.0	16.0	245	190	2.7
T40-16	40.0	16.0	660	525	7.1
T40-20	40.0	20.0	540	425	5.6
T52-26	52.0	26.0	930	730	10
T73-56	73.0	56.0	1035	830	10.8
T73-53	73.0	53.0	1160	970	14
T73-45	73.0	45.0	1600	1270	17.5
T103-78	103.0	78.0	2270	1800	25
T103-51	103.0	51.0	3660	2670	44
Thread direction: Left hand / Right hand
Thread standard: ISO10280 / ISO1720 / Other international standards

Our booth is located in Hall 6, Booth C9,10. We will display our full range of rock drilling tools and our professional team will be present to answer your questions, provide detailed product information and technical support.

We hope that we can communicate with our new and old customers through this exhibition, share our products and discuss future cooperation opportunities. We warmly welcome you and look forward to seeing you at the show.

During the exhibition, our booth attracted numerous existing customers who visited to show their support. They acknowledged our continuous efforts in product quality and technical services. These discussions with our long-standing customers about ongoing cooperation and future plans have laid a solid foundation for our long-term development in the European market.

At the same time, many new customers showed a keen interest in our products and services. They engaged in in-depth discussions with our professional team at the booth and expressed their intention to collaborate, creating opportunities for further expansion in the European market.

Through this exhibition, SINODRILLS has further strengthened its presence in the European market and expanded its customer base. In the face of future market competition, SINODRILLS remains committed to providing the highest quality rock drilling tool solutions to all our customers. We look forward to achieving even greater success in the European market!

Our booth became a focal point at the exhibition, attracting numerous customers and industry experts who expressed great interest in our products and services. Through in-depth discussions, we gained valuable insights into local market demands and trends. We also established initial cooperation intentions with several customers, laying a solid foundation for future business collaborations.

This exhibition not only demonstrated SINODRILLS' strength in the rock drilling tools industry but also strengthened our connections with the local market. We sincerely thank every customer and partner who visited our booth and look forward to maintaining close relationships with each of you in the future.

SINODRILLS will continue to uphold the principles of professionalism, innovation, and excellence, constantly improving the quality of our products and services to provide better rock drilling tool solutions for our global customers. Let’s work together to create a brighter future!

As China's leading exporter of rock drilling tools, we will showcase a full range of rock drilling products to meet diverse customer needs at this exhibition. Additionally, our professional team will provide personalized solutions to meet specific customer requirements.

We sincerely invite every customer to visit our booth and discuss potential cooperation. Looking forward to meeting you at the exhibition.

As China's leading exporter of rock drilling tools, we will be showcasing our complete range of rock drilling tools and offering tailored product solutions throughout the exhibition. The professional team at SINODRILLS is committed to meeting the specific needs of each client with personalized product offerings. Whether you are seeking cost-effective solutions, require comprehensive rock drilling tools, or are exploring partnership opportunities, we eagerly await the opportunity to engage with you in person.

We cordially invite you to visit us at Booth 5A-G016 during INTERMAT 2024!

During the exhibition, in addition to showcasing a complete range of rock drilling tools, Guizhou SINODRILLS' professional team will also provide customized product solutions tailored to your specific needs. Whether you are seeking cost-effective products, a one-stop drilling tool supplier, or simply wish to connect with us, we eagerly anticipate the opportunity to engage with you face-to-face.

Guizhou SINODRILLS is excited about the prospect of meeting you and discussing potential business opportunities and future collaborations.

Throughout the exhibition, our booth attracted a continuous flow of visitors, including many professionals who came to exchange ideas with us. The expertise we demonstrated during the discussions was highly recognized by the visitors. In addition, we had in-depth negotiations with multiple customers during the exhibition and successfully signed several orders. This exhibition not only helped us establish closer relationships with our customers but also laid a solid foundation for our product expansion in Russia and surrounding markets.

In the future, we will continue to strive to provide our customers with better quality products and services, and work hand in hand with every customer for common development.

We warmly welcome you to visit our booth and meet with us during the exhibition. Our team will be on hand to provide information and answer any questions you may have about our products and services.

We are confident that our participation in Mining World Russia 2023 will be a great success, and we look forward to meeting you at our booth, Pavilion 1 Hall 1, A3043. See you there!

Although at this special time, overseas customers were unable to visit due to the travel restrictions, it still attracted more than 3000 domestic exhibitors, which reflects the stable recovery of the domestic mining & construction industries. Under such circumstance, it also urges SINODRILLS to continuously upgrade products and improve service to optimize and enhance product competitiveness.

Despite the COVID-19 has had a short-term negative impact on the industry this year, we will continue to serve customers with efficient and excellent products as always. Hand in hand with every customer to forge ahead and develop together in adversity.

For over two decades, we have adhered to the business philosophy of “drill more, drill globally,” continuously innovating technology and optimizing products. Through relentless efforts over more than 20 years, we have earned widespread recognition and trust in the international market. Receiving the Euromonitor certification is a significant acknowledgment of our hard work and outstanding achievements over the years.

In today’s increasingly competitive global market, our ability to maintain a leading position in the rock drilling tools export industry is inseparable from the strong support of every customer and partner. It is your trust and cooperation that have shaped us into what we are today, and it will inspire us to continue forward toward a more brilliant future.

Looking to the future, we will continue to focus on technological innovation, remain true to our original aspirations, forge ahead, enhance product quality, and provide superior rock drilling solutions to global customers.

Time: In January, 2014.

Mine & Project: Bingham Canyon Mine

DTH Drill Rig Model: DM45 HP & DML

DTH Hammer Model: SINODRILLS QL60 quick hammer & World famous brand A QL60 shank hammer

Rock Formation: Rock conditions vary widely, from mild rock (not very abrasive) to very hard and very abrasive.

DTH Button Bits Configurations: QL60 171mm, 10 gauge buttons x 18mm, 10 face buttons x 18mm, two flushing holes.

Our three pieces of QL60 171mm button bits had been tested from the 7th to 20th of January, as below, it was the summary for the drilling test.

As below, it was our # 1 bit detailed drilling record from the site.

Remarks: Red box: with SINODRILLS brand QL60 quick hammer, 0.68 m/Min average speed;

Yellow box: with world famous brand A QL60 shank hammer, 0.55 m/Min average speed.

As below, it was the summary from the site manager about SINODRILLS DTH button bits:

Drill machine: KS-668 Hydraulic DTH drill machine, it is made by Kongshan China. The maximum rotation speed is 70 Rpm, and the maximum torque is 3680Nm.

Working pressure: The working pressure is 18Bar.

Rock condition: Granite

DTH hammer: GSE DHD350, Outer diameter is 126mm, the recommended wear sleeve discard diameter 114mm. The current diameter is 113mm

DTH bit: DHD350Ø140mm DTH bits, Flat front, Spherical buttons, 8x17mm gauge buttons, 7x14mm front buttons, 2 flushing hole, 35°gauge button angle.

As a kind of hard rock, granite wears the rock drilling tools very seriously. Therefore, the quality requirements of the drilling tools are also higher. Recently, our new generation of GSE DHD350 hammer has been well received by customers during its use. Our hammer completed 4900 meters of granite drilling without replacing the outer tube, and the working pressure was 18 bar. It proves the excellent performance of our products once again.

As a leading enterprise in the modern rock drilling tools manufacturing industry, SINODRILLS deeply values its employees as one of the company's most precious assets. In addition to routine health checks, this health examination included over 30 detailed specialized assessments. Furthermore, tailored examinations were designed based on the physiological characteristics of male and female employees. The primary objective was to empower employees with a comprehensive understanding of their health status and equip them with the knowledge of essential health management measures, thereby enhancing their self-care awareness.

SINODRILLS has consistently upheld the concept of sharing achievements, and this health examination is also a part of that shared success. It aims to enable employees to partake in the company's accomplishments. We will continue to provide an even more superior working environment and extensive career development opportunities. Together with all SINODRILLS employees, we are committed to shaping a brighter future.

Time: in August, 2013

Mine & project: Rio Negro, gold mining

DTH Drill rig: Atlas Copco ROC L6

DTH button bits configurations: DHD340A 115mm, flat face, hemi-spherical buttons,2 flushing holes;

Rock formation: Brecciated silica with clay matrix and disseminated sulfide mineralization, detailed photos as below:

Average life span of our DHD340A 115mm DTH button bits: 480 meters;

Average life span of a world famous brand A’s DHD340A 115mm button bits: 520 meters;

Considering different prices from our company and the world famous brand A, as below, the chart shows a drilling cost comparison between our brand and world famous brand A.

As below, here are some pictures about our DHD340A 115mm button bits performance:

Rock drill model: Pneumatic drill

Test place: Ecuador--El Oro, Azuay, Zamora

Test model: Taper bit, 11 degree, 38mm, 5*9mm, 2*7mm, short skirt.

Hole depth: 1.2m.

The taper bit after using.

The golden taper bit with 1 front hole and 1 side hole drills 175 holes with 1.2m depth per hole.

The yellow taper bit with 2 front hole and 1 side hole drills 170 holes with 1.2m depth per hole

The yellow taper bit with 1 front hole and 1 side hole drills 160 holes with 1.2m depth per hole.

Mexico trademark Certificate                                                          Peru trademark Certificate

Since its establishment 20 years ago, the company Guizhou Sinodrills Equipment Co., Ltd. has been continuously improving its competitiveness and brand image. While the overseas market share is increasing year by year, the "SINODRILLS" brand has also become the first choice of more and more overseas customers. The successful trademark registration of our company overseas not only allows the "SINODRILLS" brand to get strong protection from the corresponding countries, but also marks an important milestone in our company's brand building.

Colombian trademark Certificate                                                         Chile trademark Certificate

In the future, we will continue to activate the brand potential, keep continuous independent innovation, enhance the brand value with good product quality and strive to provide customers with better products and services.

During the visit, our general manager led the group to visit the exhibition hall of Guizhou Sinodrills Equipment Co., Ltd., office space and visit the factory production workshop via video calling. At the same time, he gave a detailed report on the current situation of the company, business segments and overseas sales. In the subsequent discussion and exchange meeting, leaders at all levels had a detailed exchange with our management team and gained an in-depth understanding of our development history, operation, R&D investment, and development planning.

At the meeting, the leaders fully recognized our company’s achievements in the past almost 20 years of development and introduced Wuxue City’s investment policy for our company in detail, and made in-depth communication about the land use and project cooperation, and reached a preliminary cooperation agreement.

In addition to the regular physical checkups, blood testing, occupational disease examinations and other items, the program was also customized with high-end items according to the physiological characteristics of men and women, so that all employees can have a more comprehensive understanding of their physical health and enhance their self-care awareness.

Our company has always adhered to the business philosophy of “co-creation and sharing”, and has put this philosophy into practice. As one of the regular work, the staff physical examination also allows all people in SINODRILLS to share the achievements made by the company.

“Born as a summer flower and living as brave as Mulan”. No matter what roles women play and where they live, they have demonstrated responsibility and commitment with their own contributions. Soft shoulders carry heavy responsibilities and women take their roles. With hard sweat and unremitting struggle, women “hold up half the sky” in their careers and families, and make their own extraordinary achievements. 

On the occasion of this holiday, we would like to deliver our gratitude to each female compatriot for your contributions and wish you all a happy holiday!

self-drilling anchor system increase the load-bearing capacity of the entire structure and act as a group of elements, withstanding tensile and shear forces acting on the self drilling anchor system. The center-to-center distance of nails must be chosen so that they are able to act as a complete nailing system. Prior to nail installation, the excavation face is generally supported by shotcrete, precast concrete elements, mesh, or geotextiles. The design of a nail head construction depends on the application and the intended lifetime of the structure.

SINODRILLS R Thread Self drilling hollow anchor bars (IBO)