Drill Bit Shank - Morse Taper Shank

Morse Taper Shank

The Morse taper twist drill bits pictured right are used in metalworking. The full range of tapers is 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 a Morse taper and this allows the chuck assembly to be removed and directly replaced with the shank of a Morse taper drill bit. A range of sleeves may be used to bring the size of the smaller Morse tapers up to the size of the drive spindle's larger taper. Sockets are also available to extend the effective length of the drill as well as offering a variety of taper combinations.

The detail image shows a Morse taper shank on a 16 mm diameter drill bit.

• Simple to manufacture on a lathe
• Cannot be held in a chuck or collet
• High torque transmission provided the bit is driven hard into the workpiece
• Very accurate centering