Drills are cutting tools that are used to remove material in order to create holes, which are almost always circular in cross-section. Drills come in a variety of sizes and shapes, and they can create various types of holes in a variety of materials. Drill bits are typically attached to a drill, which powers them to cut through the workpiece, typically by rotation. In the chuck, the drill will grasp the upper end of a bit known as the shank.
Drills have standard drill bit sizes. A comprehensive drill bit and tap size chart lists metric and imperial drill sizes, as well as the necessary screw tap sizes. Certain specialised drill bits can also create holes with a non-circular cross-section.