Abstract: A safety key for a toolroom lathe chuck having (1) a housing having a top end, a bottom end and an internal bore opening on the bottom end and extending towards the top end, (2) a sleeve concentrically surrounding said housing and axially slidable thereon between a first position and a second position, (3) a handle connected to and extending transversely to the top end of the housing, (4) a key member sized to be movably received in the internal bore of the housing at the bottom end thereof, (5) securing apparatus for securing the key member to the sleeve, (6) a spring for biasing the sleeve into its first position when no axially downward pressure is applied to the sleeve, whereby the key member will be completely withdrawn into the internal bore of the housing, and (7) a lever attached to the handle for applying axially downward pressure to said sleeve, the lever being adapted to provide such downward pressure to the sleeve when the lever is moved towards the handle, whereby the sleeve may be moved axially