A locking washer is preferably assembled to the top of an internally threaded bushing and retained on the bushing by force fit into a groove on the bushing or by adhesion. The washer includes a peripheral collar and an integral tang which diametrically extends into a central opening of the collar. When a screw is inserted into the threads of the bushing the tang becomes bent over and thereafter when the screw has been further advanced the tang longitudinally extends between the threads of the screw and the bushing. More than one washer may be used.