A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5975-01-302-2107
NSN 5905-01-445-5923
NSN 5935-00-644-9978
NSN 5960-00-515-7366
NSN 5855-00-797-8217
NSN 2925-01-528-7333
NSN 6610-00-456-0485
NSN 6130-01-421-2705
NSN 6150-01-468-5675
NSN 5915-01-564-4540
NSN 6135-00-284-1406
NSN 6610-01-035-1252