A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6240-01-633-3863
NSN 6135-00-789-2865
NSN 5965-01-175-4839
NSN 6685-01-161-9677
NSN 5945-01-152-2780
NSN 6240-01-103-3081
NSN 5975-01-244-2268
NSN 5945-00-181-9558
NSN 5905-00-188-9029
NSN 5925-00-495-6519
NSN 6685-00-724-8861
NSN 5999-01-430-2229