drill bit

Drills are cutting tools used to remove material to create holes, almost always of circular cross-section. Drills come in many sizes and shapes and can create different kinds of holes in many different materials. In order to create holes drill bits are usually attached to a drill, which powers them to cut through the workpiece, typically by rotation. 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.The term drill bit may appear throughout this page and correctly means drill. Devices for driving drills are commonly laxly and erroneously referred to as drills but are correctly called various names by their design:

Hand drill - a hand-held, hand powered driver of drills
Electric drill - a hand-held electrically powered driver of drills
Bench drill - a powered drill driver mounted in a sliding frame commonly bolted down to a work bench. Larger ones are referred to as pillar drills In the U.S. commonly referred to as a drill press
Pillar drill - depending on height, either bench or floor mounted frame comprising a single supporting column that supports the drill-driving assembly above a work table, both of which are commonly adjustable.
Radial drill - a large pillar drill where the pillar supports a horizontal arm upon which a drilling head is mounted. This arrangement permits r (distance from the pillar) and theta (distance around the pillar) movement of the head for positioning of the drill for hole alignment.

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