Sharpening Techniques for Twist Drills

Bench Grinder

• You can use a bench grinder to sharpen twist drill bits. A bench grinder is a moderately large piece of machinery equipped with a spinning grinder wheel. Remove the twist drill bit from the drill. After turning on the bench grinder, hold the bit on an angle while pressing lightly onto the grinder wheel to sharpen the bit. This process can be repeated many times for one bit once it becomes dull again.

Sharpening By Freehand

• Twist drill bits can also be sharpened via a freehand method. Begin by holding the drill bit on your forefinger, with the bit's cutting lip horizontal and the axis of the drill at an angle of about 60 degrees. Press the bit against a woodworking protractor or grinding wheel while maintaining this angle. Move the bit with your hand in three distinct motions to sharpen the bit: to the left, in a clockwise motion and then downward.

Grinder and Jig

• Sharpening drill bit jigs can also be used with a bench grinder to sharpen your twist drill. After mounting the drill bit jig onto the tool rest on the grinder, position the drill bit into the jig and turn on your grinder. Hold the bit firmly against the edge of your sharpening jig. Slide the bit forward and back along the jig while the grinding wheel is running to sharpen the bit.

Considerations

• When using a bench grinder to sharpen twist drill bits, always wear protective gear, including goggles and work gloves. Drill bits can snap in two if you press too hard on the grinding wheel. Twist drill bits will need to be replaced after repeated use. Follow your drill manufacturer's manual to determine when and how often you should change the bits.