A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5910-01-352-8886
NSN 6620-01-535-0070
NSN 6240-01-550-1178
NSN 5996-00-551-1097
NSN 6685-01-033-4648
NSN 6130-00-274-6351
NSN 5835-01-267-3388
NSN 5985-00-629-1992
NSN 6240-01-303-0142
NSN 5975-00-035-6524
NSN 5990-01-241-2479
NSN 5930-01-084-7186