How is a DHH drill bit sharpened?

• A. By heating the worn or rounded edges using specialized grinding tools
• B. By grinding the worn or rounded edges of the bit's cutting surfaces, usually with specialized grinding tools
• C. By soaking the bit in a solvent to sharpen its edges
• D. By using a standard wood file on the bit edge

Answer: (B)

Sharpening a DHH drill bit means restoring the actual cutting edges by removing a small amount of material from the worn, rounded edges with controlled grinding. The goal is to bring back the sharp geometry of the cutting surfaces so the bit can bite into rock effectively again. This requires using tools designed for drill-bit sharpening to maintain the correct angles and symmetry between both cutting edges. Heating the edge can soften or damage the temper, soaking in solvent won’t create a sharp edge, and a standard wood file can’t reproduce the precise edge geometry required. By grinding with the proper equipment, you remove precisely the right amount of material, keep the edges true, and help the bit cut efficiently and stay balanced in the hole.