A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5985-01-659-4501
NSN 5905-01-160-7110
NSN 5965-00-267-4173
NSN 5915-00-737-0924
NSN 5985-01-500-0880
NSN 5935-01-397-9909
NSN 6110-01-168-8600
NSN 5915-01-024-7293
NSN 5998-01-059-1761
NSN 5945-01-606-7297
NSN 5985-01-371-2188
NSN 5990-01-416-6009