What is a center drill?

A center drill is a small bit with a thin nub on both ends used to make a small hole at the center of a work. We use center drills before drilling holes with twist drills, and to help support parts before placing them on a center (on the lathe). Twist drills are designed to flex (or “wander”) before beginning to cut. Center drills are much stiffer, ensuring that you start cutting a hole in the accurate, desired location.