Other names: root mother, anti-loosening nut, nazi.
　

Purpose: to lock the outer joint of the harness or other pipe fittings.

The working principle of the nut is self-locking by the friction between the nut and the bolt. However, the reliability of this self-locking under dynamic load will be reduced. In some important occasions, we will take some anti-loosening measures to ensure the reliability of the nut locking. The use of a lock nut is one of the anti-loosening measures.