Drill chuck

Drill chuck

A drill chuck is a specialised self-centering, three-jaw chuck, usually with capacity of less than 0.5 in (13 mm) and rarely greater than 1 in (25 mm), used to hold drill bits or other rotary tools. This is the type of chuck that a machining layperson is most likely to be familiar with.
Some high precision chucks use ball thrust bearings to reduce friction in the closing mechanism and maximizing drilling torque. One brand name for this type of chuck, which is often used generically, is Super Chuck.[citation needed]
A pin chuck is a specialized chuck designed to hold small drills (less than 1 mm (0.039 in) in diameter) that could not be held securely in a normal drill chuck. The drill is inserted into the pin chuck and tightened, the pin chuck is then inserted into the larger drill chuck so that the operation can continue. Pin chucks are also found on high speed rotary tools, such as die grinders and jig grinders.