How to Grind Wood Drill Bits

Grinding method: When grinding, keep the main cutting edge on one side of the drill bit horizontal and slightly higher than the horizontal plane passing through the center of the grinding wheel. Defects with high flank. Keep the correct angle between the axis of the drill bit and the grinding surface of the grinding wheel (half of the top angle of the drill bit). The right hand is in front and the left hand is behind, hold the drill bit to contact the grinding surface of the grinding wheel, the right hand rotates the drill bit around its own axis according to the rotation direction during work, apply appropriate pressure, the left hand cooperates with the right hand to make a synchronous downward movement, the left hand moves down. The pressure and magnitude of the pressure depends on the size of the angle. Large-diameter drills should be moved laterally, and the two backs should be ground frequently. When the drill tail swings, it shall not exceed the horizontal plane to prevent the negative clearance angle from being ground. When the cutting edge is about to be ground, it should not be ground from the back of the blade to the direction of the cutting edge to avoid annealing of the cutting edge. For small-diameter drills, do not pick up the drill after grinding one side, and directly turn it to the other side for grinding. Since the position of the hand remains unchanged, the two main cutting edges of the drill are not easy to appear one high and one low. When grinding the chisel edge with a small diameter drill, it is easy to control the width and symmetry of the chisel edge from the outer side of the flank and then move to the corner of the grinding wheel. It is not easy to control the amount of grinding. For large diameter drills, the chisel edge can be shortened directly with the fillet of the grinding wheel.