A Spotting Drill's purpose is to create a small divot to correctly locate the center of a drill when initiating a plunge. However, some machinists choose to use these tools for a different reason – using it to chamfer the top of drilled holes. By leaving a chamfer, screw heads sit flush with the part once inserted.

What is the purpose of spot drilling?

The primary purpose of a spot drill to make a "dimple" in the workpiece so that the twist drill does not deflect and "walk" off-center and the hole is drilled in the correct location. Our carbide NC spot drills are stocked standards, with a 90° or 120° and a a 140° point angle.

What is the difference between a spot drill and a center drill?

Center drills are intended to be used to create a hole suitable for a lathe center. They have a 2 part tip that has a small pilot as well as the larger countersinking area of the bit. ... The broader angle of a true spot drill means the tip of the twist drill cuts first, which makes for a more accurate hole.