Self-Locking Screw

A square-threaded screw jack is a mechanical device widely used for lifting heavy loads or applying considerable force. One of the key features that can make a screw jack more effective and reliable is its self-locking capability.

A square-threaded screw jack carrying a load is considered self-locking if the screw retains its position eve...

Consider a square-threaded screw jack carrying a load. If the screw retains its position even after the moment is removed, it is called self-locking.

This happens if the frictional force direction reverses and the reaction force acts on the other side of the thread's normal.

Here, the static friction angle can be larger or equal to...