A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6685-00-661-2347
NSN 6130-01-117-7282
NSN 6685-00-960-7667
NSN 5950-01-044-1378
NSN 5960-01-481-3722
NSN 6110-01-604-9233
NSN 5835-00-733-9145
NSN 4140-01-132-6612
NSN 6135-00-967-3112
NSN 5910-01-004-6419
NSN 5930-01-467-4832
NSN 2925-01-064-3729