A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5925-01-500-5407
NSN 6620-01-456-0529
NSN 6620-00-586-6460
NSN 5965-00-087-6767
NSN 6610-01-333-9543
NSN 5855-01-474-3325
NSN 4140-01-483-2297
NSN 6685-01-081-5225
NSN 5960-00-932-3067
NSN 6145-01-462-2460
NSN 5998-00-426-6827
NSN 6130-00-006-5377