Screw Jacks are referred jack screws, which use a long threaded rod to position a matching nut at any position along the length. They are designed for both tensile & compressive loads and work in any orientation or mounting position. Screw jacks use an acme along the threaded rod, which gives the screw strength and resistance to the large loads imposed on most screw jacks. Its typical uses include car-locks, railway applications, securing connectors in computer, electronic equipment and linear actuators. Screw jacks use the mechanical advantage of threads to lift the work piece. There are two types of screw jacks such as ball screw jacks and machine screw jacks. Ball screw jacks use recirculating ball bearings on a precision pitch screw for fast, efficient lifting. Machine screw jacks use screws with less pitch and usually do not have ball bearings.