A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6685-00-608-0318
NSN 6110-00-962-2881
NSN 6685-01-415-6424
NSN 5990-01-408-6554
NSN 5998-01-037-4454
NSN 5935-01-364-0507
NSN 5965-00-612-0072
NSN 5965-01-249-6349
NSN 6320-01-054-3046
NSN 5835-01-476-5584
NSN 5920-01-467-2079
NSN 5910-00-900-6287