Drill bit shank from 0 to 7. The Morse taper allows the bit to be mounted directly into the spindle of a drill, lathe tailstock, or (with the use of adapters) into the spindle of milling machines. It is a self-locking (or "self holding") taper of approximately 5/8" per foot that allows the torque to be transferred to the drill bit by the friction between the taper shank and the socket. The tang at the end of the taper is only for ejecting the drill bit from the spindle, with the aid of a drift. The arbor of a drill chuck is often
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