Locking nut is a kind of nut widely used in machinery and other industries. Its working principle is to use the friction between the nut and the bolt to self-lock. 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 the nut locking.

The anti-loosening effect of the locking nut mainly depends on the interaction force between the nut and the bolt meshing thread. There are many ways to improve the interaction force between the meshing threads, such as the structural improvement of the nut thread, the roughening of the nylon nut, and the surface treatment of the thread.

Lock nuts are used in many places, most of which are precision equipment, such as machine tools, centrifuges, air conditioners, printing and other equipment, and even railways and nuclear industries. This is due to the ease of installation, not easy to loosen, and long service life of lock nuts, which are widely used in precision mechanisms.