Product Description   Top Quality Worm Gear Screw Jacks Load Up to 200 Ton Machine& Ball Screw Jack Actuators Features: 1. Suitable for heavy load, low speed and low frequency; 2. Main components: precision trapezoid screw pair and high precision worm gear pair; 3. Compact design, small volume, light weight, wide drive sources, low noise, … Continue reading China Good quality Swl Series Linear Motion Elevator Lifting Adjustable Trapezoidal General Ball Worm Gear Screw Jack for Scaffolding Construction Swl Series Worm Screw Jack gear patrol