A chuck is a heavy mechanical device mounted on a machine spindle that grips round or hexagonal stock, or cutting tools. It typically uses three or four adjustable jaws that close radially around the object. Lathes use large chucks to hold spinning metal, while mills and drill presses use smaller chucks to hold spinning drill bits.
Throw that piece of aluminum in the three-jaw chuck and face it off.
Related terms
Four-jaw
Shop name for an independent four-jaw lathe chuck, each jaw adjusted separately to center or offset work.
Soft jaws
Vise or chuck jaws of aluminum or mild steel, machined in place to cradle a specific part.
Chuck key
The T-handle wrench that opens and closes a geared drill chuck or lathe chuck, never left in the chuck.
Collet
A slotted, tapered sleeve that squeezes evenly around a tool shank or bar stock to grip it accurately.