A washer is a thin plate typically diskshaped, but sometimes square with a hole typically in the middle that is normally used to distribute the load of a threaded fastener, such as a bolt or nut. Other uses are as a spacer, spring Belleville washer, wave washer, wear pad, preload indicating device, locking device, and to reduce vibration rubber washer. Spring washers, which have axial flexibility are used to prevent fastening or loosening due to vibrations. Locking lock washers prevent fastening or loosening by preventing unscrewing rotation of the fastening device. Specifications. Height 0.1 in.. Width 1.55 in.. Length 1.55 in.