How to Sharpen a Step Drill
A step drill is a graduated drill used to make holes in thick metal sheets. The first step on the drill creates a rather small hole but each subsequent step gradually enlarges it. Step drills can be difficult to sharpen but if the bit can be removed from the drill then there are a few methods that may work.
Grind the first step like you would any other drill bit. Put the drill in a clamp that exposes only the first step. Run the edge along the grinding wheel in short, quick motions until the bit looks sharp enough for your needs.
Move the clamp lower on the bit so that 20 mm of the second step are exposed.
Adjust the clearance angle on the grinding machine enough to accommodate the larger step.
Position the edge of the second step against the right corner of the grinding wheel. Grind the drill while pivoting the bit up and down along an axis. If your drill has more than two steps, repeat until finished.
- Always wear gloves when your hands are near a rapidly rotating grinding wheel.
- drill image by Grebenshchikov from Fotolia.com