Button bits have the advantages of high drilling speeds, stable and long service life, and are widely used in mining, quarrying, water wells, construction and other fields.

Despite their wear resistance, button bits cannot be self-sharpened during the drilling process. Even the most wear-resistant spherical button bits can develop flat wear or micro-cracks, leading to reduced drilling speeds and a shortened lifespan. Therefore, in order to reduce bit consumption and lower drilling costs, timely re-sharpening of button bits is necessary.

1. Hazards of not re-sharpening the bit timely?

-All components of the drill string and rig will bear excessive loads.

-Premature fatigue failure on all drilling products

-Slower drilling

-Increased downtime due to unscheduled maintenance.

2. What's the best time to re-sharpen button bits?

The ideal moment to re-sharpen button bits arrives when the wear flat ratio reaches 25-50%, carbides protrusion falls below half its diameter. Meanwhile, a snake-skin pattern or thermal cracks may appear on the surface of the carbides, indicating the need for re-sharpening.

3.  How to re-sharpen the carbide of button bits?

Generally, a grinding cup, typically made of diamond, is used for re-sharpening carbides. It operates at high speed and makes vertical feeds along the axis of the carbides.

In many cases the carbide may wear faster than the body material of the bit, it's often necessary to remove some body material to expose proper height of the carbide. This height should not be less than 1/2 of the carbide diameter and not exceed 3/4 of it. Avoiding the removal of excess material is crucial as it can lead to carbide failure.

-When grinding, choose grinding cups that are closest in diameter and shape to the carbide being sharpened.

-Rotate the grinder in a cylindrical way around the carbide, consistently aligned with the carbide’s axis. Wobbling tools can damage the carbide.

-Remove as little material as possible, maintaining the original carbide shape.

 -Use adequate coolant flow to prevent damage to the carbide from overheating.

Proper and timely re-sharpening of carbides buttons extends the service life of the drilling string; enhances drilling speed; reduces stress on drill tools and drill rig components; minimizes drilling tools failure chances; reduces downtime; and boosts drilling efficiency.

Practice has shown that correctly re-sharpened carbides can help save up to 35% in operational costs!