A pointed, spiral piece of metal secured at the end of a ramrod and used to remove a lead ball or patch from a muzzle loading gun.

A linear motion bearing where the inner race is helical. Each ball screw assembly consists of a screw with a precision ground or rolled helical groove, a nut (the outer race) with an internal groove, and a circuit of precision steel balls that recirculate in the grooves between the screw and nut. This anti-friction design converts torque to thrust [..]

(((ball screw)))[[glo:Ballscrew]] A type of lead-screw that uses small hardened steel balls between the nut and screw to reduce friction. Ball-screws have very low friction and backlash, but are usual [..]

A device for transforming rotary motion to linear, or vice versa, incorporating a threaded rod portion and a nut consisting of a cage holding many ball bearings.

See Worm