Twist drill bit grinding need to prepare: sander, marker, blade.

1, first of all, take out the twist drill bit, with a marker to mark the twist drill bit needs to be sanded place, see the picture below.

2, next start the sander, use the blade to clean up the surface of the grinding wheel, as shown in the figure.

3, the following twist drill bit to the edge of the grinding wheel can be sanding, so you need to pay attention to pay attention to safety, as shown in the figure.

4, the last twist drill bit can be polished, specifically as shown.