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 (well) what became the Hughes Tool Company. This bit employed two conical steel rolling elements with milled teeth that engaged the formation, when the device was rotated, to produce the cutting action. This design represented a significant improvement in drilling performance over the so-called "fish tail" scraper type bits commonly used in rotary drilling at the time, and over the next two decades, rotary drilling with rolling cutter bits largely replaced all other drilling methods in the oilfield. The significance of the Hughes Two-Cone Drill Bit was recognized on its 100th anniversary when it was designated a Historic Mechanical Engineering Landmark