The actuator has a standard 24.2 efficiency rating, drives at 2 hp maximum, and is available with top plate, clevis end, or threaded end mounts. It can be driven by a manual crank or gear motor connected to the horizontal worm shaft. Translating contact is made between the bronze worm gear and the turning worm shaft. The lift screw is propelled back and forth by sliding contact of the machined inner diameter of the worm gear. The actuators are self-locking and hold heavy loads in position indefinitely without creep.