Travelling nut screw jacks are also called as rotating screw jacks. In this design, the lead screw is fixed to the worm gear and rotation of the worm gear causes rotation of the lead screw. A flanged traveling nut is placed on the lead screw; therefore and the nut translates along the lead screw when the worm gear rotates. The load is carried by the traveling nut which is generally made of bronze material for improved durability. The linear travel speed of translating nut depends on the thread size, pitch and rotation ratio of worm gears. This design is proper for applications where the physical space does not allow the lifting screw to extend below the housing. Rotating screw jacks are also useful when it is not possible to fully guide the load.