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.
Bit (key) One American manufacturer, Eagle Lock Company, used letters exclusively for bitting codes. This is a type of key where the individual cuts are designed to engage chisel-pointed pins in high-security locking systems manufactured by Medeco and Emhart. These angled cuts are designed to lift each tumbler to a predetermined height to the shear line and to rotate them to a specific angle to engage a sidebar mechanism (Medeco) (this is also used in Schlage Primus) or to line up an interlocked pin to such a position to where it would allow the plug to rotate (Emhart). Bit (key) The bit