screwdriver

A tool for turning screws in or out of their places. It has an end like a blunt chisel, which enters the nick in the screw-head. screw-gear, s. Mach.: The worm and worm-wheel, or endle screw and pinion. screw-jack, subst . A lifting-jack, in which the power consists of a screw rotating in a nut in the body of the tool. [JACK.] screw-key, screw-wrench, s. 1. A spanner for the articles which socket upoמ the mandrel-screw. 2. The lever of a screw-pre ; a form of key used with lock-faucets. screw-lock, s. Locksmith.: A lock, of which the e ential feature is an opening bar, which is detained by a screw when in a locked position.