A toothed or square-drive key that turns the scroll or jaw screws of a chuck. The first safety rule taught on any lathe or drill press is that the key comes out of the chuck the moment it is tightened, because a key left in a spinning chuck is thrown out at speed. Spring-loaded safety keys that pop out when released exist for exactly that reason.
Hand stays on the chuck key until it's out of the chuck, every time, I don't care how quick the job is.
Many shops keep the key on a lanyard or in a holder by the switch, so putting it away becomes part of starting the machine.
Also heard as
- key
- chuck wrench
Related terms
Four-jaw
Shop name for an independent four-jaw lathe chuck, each jaw adjusted separately to center or offset work.
Collet
A slotted, tapered sleeve that squeezes evenly around a tool shank or bar stock to grip it accurately.
Thumb detector
Shop joke name for any pinch point, blade or mechanism that is especially good at finding fingers.