Spring washers

Spring washers are disks of metal that are formed in an irregular shape so that when the washer is loaded it deflects, acts like a spring, and provides a preload between two surfaces.  Spring washer types include adjustable spacers, Belleville washers, bowed or curved washers, conical washers, finger washers, and wave washers. Spring washers are typically used in applications where assemblies need a part to take up play, eliminate rattle, maintain assembly tension, compensate for expansion or contraction in materials after assembly, or to absorb intermittent shock loads and provide a controlled reaction under dynamic loads.