It’s been nearly a century since the invention of DTH hammer. It was originally used for drilling and blasting in quarrying and surface mining.

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.