Countersinks are used to deburr holes. Countersinks are characterized by a bevel-shaped cutting point. For deburring, the point angle is usually at 60° and is generally at 90° for countersunk bolts. There are also countersinks with a point angle of 75° and 120°. A point angle of 75° is suited to rivet head countersinks and a point angle of 120° to metal rivet countersinks. There is normally an odd number of cutting edges so that the countersinking process is smoother.