How to drill the center hole of chuck fixture?

There are two commonly used methods of drilling center holes.

(1) Drill a center hole on the lathe, clamp the piece on the chuck, extend it as short as possible, align the flat end of the rear lathe, and then shake the tailstock handwheel slowly and evenly to drill the center hole. After drilling to the size, let the center drill remain in the original position for a few seconds to make the center hole round before exiting; or feed gently so that the cutting edge of the center drill cuts a thin layer of chips from the 60° cone surface to reduce the surface roughness of the center hole. During the process of drilling the center hole, you should also pay attention to retracting the tool frequently, clearing the chips in time, and providing sufficient cooling and lubrication. This method is suitable for shaft workpieces with smaller diameter and lighter weight.

(2) Drill the center hole after setting the center. For workpieces with larger diameters, heavier weights, or more complex workpieces that cannot drill the center hole on a lathe, the center is often marked on the workpiece, and then the center hole is drilled with an electric drill on a drilling machine or on a boring machine.