... Worm Shaft, Taper Roll Bearings, Seals, Housing, Self-locking Trapezoidal Screw,etc;3. Safely self locking, Positioning Precision, Heavy Duty, Uniform ... ,Pressing,Pushing,Rolling.5.Availabity: Manual Operation and Electrical Operation are available;6.Multiple Screw Jack Systems are availbale and fully ... 0.03 ~ 21.5 HP;10.Trapezoidal Screw Diameters Range 20 ~100 mm;Screw Pitch Range 5 ~ 16 mm;and its ...