Drill chuck

A drill chuck is a specialised self-centering, three-jaw chuck, usually with capacity of 0.5 in (13 mm) or less and rarely greater than 1 in (25 mm), used to hold drill bits or other rotary tools. This type of chuck is used on tools ranging from professional equipment to inexpensive hand and power drills for domestic use; it is the type a person who does not normally work with machine tools is most likely to be familiar with.