... , and complete screw jack. Determination of type1. Type 1 = Screw jack with translating screw Type 2 = Screw jack with travelling nut 2. ... Size = 2.5, 5, 10, 15, 20, 25,35 (×10KN) 3. M = Low worm gear ratio with ... start lifting screw P = High worm gear ratio with single start lifting screw 4. Direction of lifting screw ... reserved swl series worm screw elevator, screw jack, lift