What is self locking of screw jack?

Self-locking of a screw jack refers to the ability of the screw mechanism to prevent reverse motion when a load is applied, thus maintaining its position without additional support. This occurs when the friction between the screw and the nut is greater than the load's tendency to cause the screw to unwind. Self-locking is advantageous in applications where safety and stability are critical, as it reduces the risk of accidental lowering or movement of the load. However, it may also require higher torque to raise the load due to the friction involved.