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 meshing threads, such as structural improvement of nut threads, nylon roughening of nylon nuts, and surface treatment of threads.
Points to note during the operation of the lock nut:
1. Use two same nuts to screw on the same bolt, and add a tightening torque between the two nuts to make the bolt connection reliable.
2. A threaded hole is drilled from the outer surface of the nut to the inner thread surface for screwing in small-diameter countersunk screws. The purpose is to apply a centripetal force to the thread to prevent the
lock nut from loosening.

At present, the
lock nuts of better quality on the market are inlaid on the inner surface of the nut with copper small pieces that are consistent with the thread of the lock nut, which is used to prevent the radial jacking screw from directly contacting the locked thread and causing damage.