WASHER, SPRING, ZINC, 20MM THRU HARDENED

Spring Washers, also called Split Lock Washers, provide a vibration resistant function, they consist of ring split at one point and bent into a helical shape, this causes the washer to exert a spring force between the fastener’s head and the bearing face which maintains the washer hard against the face and the bolt thread hard against the nut or threaded hole, creating more friction and resistance to rotation.