Locknuts are used to mount bearings securely on shafts or clamping bushes. Locknuts also enable bearings to be removed again. Locknuts are fitted with four grooves, all equidistant from each other, into which the tabs of the locking ring can be bent. (Locking) rings are used to prevent nuts from working loose. Locking rings prevent (lock) nuts from working loose. Locking rings come in various forms and, in contrast to other types of rings, are not smooth or flat.