A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5990-01-414-7618
NSN 6685-01-044-6178
NSN 6650-01-422-1037
NSN 5945-00-722-9695
NSN 6130-01-379-1702
NSN 5920-00-806-3152
NSN 6220-01-246-3240
NSN 4140-01-484-8340
NSN 5925-01-467-9910
NSN 5910-01-313-2456
NSN 6135-01-633-8502
NSN 5975-00-210-4652