The positive locking methods use a split pin, a screw, a lock plate, or a tab washer to lock the nut. However, the tendency of unscrewing is reduced if the threads of the nut and bolt are of a good fit. The various locking devices for nuts are classified into positive and friction types. To prevent this, some means of locking the nut from unscrewing is necessary.
This consequently may result in a serious breakdown. Under such conditions, because of the working clearance existing between the mating threads, the nut develops a tendency to work loose or unscrew by itself. In addition, sometimes, they are required to carry varying axial loads also, for example, as the crossheads and connecting rods of an engine. The types of nuts and bolts used in the moving parts of machinery will be subjected to continuous vibration. When a nut is tightened over the bolt, a small working clearance exists between the threads of a nut and bolt, even in the highest class of fits. You might like: What Are The Types of Wrenches? How To Use? Methods of Nut Locking #1 Locking of Nuts This nut can be easily operated by the thumb and a finger and is used where it must be adjusted frequently.
