A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5960-00-860-7710
NSN 5930-01-067-4927
NSN 6685-01-625-3386
NSN 6130-01-423-8905
NSN 6685-00-035-6852
NSN 5975-01-526-8453
NSN 6610-01-256-7938
NSN 5835-01-045-6371
NSN 5965-00-702-7257
NSN 5930-00-258-6085
NSN 6110-00-896-5790
NSN 6240-01-534-0762