Topic summary
Drill bit

Type of cutting tool From top: Spade, brad point, masonry, and twist drills bits Drill bit (upper left), mounted on a pistol-grip electric drill A set of masonry drills A drill bit is a cutting tool used with a drill to remove material and create holes, typically with a circular cross-section. Drill bits are available in various sizes and shapes, designed to produce different types of holes in a wide range of materials. To function, drill bits are usually mounted in a drill, which provides the rotational force needed to cut into the workpiece. The drill will grasp the upper end of a bit called the shank in the chuck. Drills come in standardized drill bit sizes. A comprehensive drill bit and tap size chart lists metric and imperial sized drills alongside the required screw tap sizes. There are also certain specialized drill bits that can create holes with a non-circular cross-section. Characteristics Drill geometry has several characteristics: The spiral (or rate of twist) in the drill bit controls the rate of chip removal. A fast spiral (high twist rate or "compact flute") drill bit is used in high feed rate applications under low spindle speeds, where removal of a large volume of