2. Worm gear ball screw jack with load 1 ton - 35 tons. 3. Bevel gear screw jack with load 2.5 ton - 50 tons. Different Versions of Screw Jack For Lifting System 1. Translating Screw Version: The rotation of the worm gear acts directly on the lift screw and the lift screw translates linearly. Unless the end of the lift screw is fixed (dependent