Bench grinders are common household tools that are effective at giving new life to drill bits that have become dull or blunt. The job requires practice to avoid damaging the bit. This particularly applies to small bits.
Step 1: Preparation
Put on protective glasses or goggles. The grinding wheel should be of fine grit and should be flat.
Step 2: The point angle
The bit should be held at a 60 degree angle to the grinder. Grind until this edge is created.
Step 3: Lip clearance
To create the lip clearance, move the bottom end of the bit towards the grinder to increase the angle. At the same time, rotate the bit clockwise a quarter of a turn.
Step 4: Check
The cutting angle, cutting edges and the angle of the lip clearance should be the same on both sides of the bit.