... Pushing, Pulling and Rolling Linear Motions. Worm Gear Drive Screw Jack Accessories: Protective Tube, Rubber Bellows, Electric Motor, Hand ... , Swivel Plate and Trunnion Base. Worm Gear Drive Screw Jack Features: * Top End: Top Plate,Clevis End,Threaded ... Device Available. * Special Custom Design Available.Worm Gear Drive Screw Jack Materials: * Lifting Screw: steel C45 (optional: stainless steel) ...