Drill bit shank shaft and shank, is usually of the same diameter. It is held usually in a three-jaw drill chuck. Bits of diameter too small to grip firmly can have straight shanks of larger diameter than the drill, which can be held firmly in a standard size collet or chuck. Large drill bits can have straight shanks narrower than the drill diameter so that they can be fitted in chucks not able to chuck the full diameter. Such a drill bit is called a reduced-shank or blacksmith's drill. For example, this allows a bit to be used in a pistol-grip drill's chuck.
Drill bit screwdriver tip to engage, making use of a screwdriver impossible. The extractor is pressed against the damaged head and rotated counter-clockwise and will tend to jam in the damaged head and then turn the screw counter-clockwise, unscrewing it. For screws that break off deeper in the hole, an extractor set will often include left handed drill bits of the appropriate diameters so that grab holes can be drilled into the screws in a left handed direction, preventing further tightening of the broken piece. A spade drill bit for metal is a two part bit with a tool holder and an