A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6685-01-367-3675
NSN 5925-00-850-1947
NSN 5975-01-374-6693
NSN 5915-00-351-7355
NSN 5930-01-602-8635
NSN 6650-00-161-4122
NSN 6135-00-823-3034
NSN 5910-01-068-8019
NSN 6220-00-021-9040
NSN 6110-01-424-3101
NSN 5895-00-203-2379
NSN 6110-01-162-9677