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 and the rotating flutes carry away the dust. Rotating the bit also brings the cutting edges onto a fresh portion of the hole bottom with every hammer blow. Hammer drill bits often use special shank shapes such as the SDS type, which allows the bit to slide within the chuck when hammering, without the whole heavy chuck executing the hammering motion. Masonry bits of the style shown are commonly available in diameters from 3 mm to 40 mm. For larger diameters, core bits are used. Masonry bits up to long can be used with hand-portable power tools, and are very