What Are The Basic Screw Motions?

Four distinct screw motions produced by actuating screws and nuts may result in motion-converting actions.

The two most common involve torque conversion to thrust.

In Figure 17, the screw is rotated (torqued) and the nut moves linearly producing thrust or the nut is rotated (torqued) and the screw moves linearly. The two less common motions involve thrust conversion to torque.

In Figure 18, the nut undergoes a linear force (thrust) and the screw rotates or the screw undergoes a linear force (thrust) and the nut rotates. These two motions are commonly referred to as “backdriving”, “overhauling”, or, improperly, “reversing”.

Basic Screw Motion - Torqued


Basic Screw Motion - Thrust