The main purpose of the lock nut: to lock the outer joint of the wire or other pipe fittings. The working principle of the nut is to use the friction between the nut and the bolt for self-locking. However, the reliability of this self-locking will be reduced under dynamic load. In some important occasions, we will take some anti-loosening measures to ensure the reliability of nut locking. The lock nut is one of the anti-loosening measures. The anti-loosening effect of the lock nut mainly depends on the interaction force between the nut and the bolt engaging thread. There are many ways to improve the interaction force between the meshing threads, such as the improvement of the thread structure of the Spirax nut, the nylon roughening of the nylon nut, and the surface treatment of the thread, etc.
   Some other names for lock nuts: root nut, lock nut, nut. They actually refer to the same thing. Its application range is still very wide, such as the application range of the automobile industry - cars, trucks, buses, compressors, construction machinery, wind power generation equipment, agricultural machinery, foundry industry, drilling equipment, shipbuilding industry, military, mining equipment, Oil drilling rigs (onshore or offshore), utilities, rail transit, transmission systems.