A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6150-01-327-2009
NSN 5998-01-469-7836
NSN 6105-01-454-6564
NSN 5985-01-482-1375
NSN 5920-01-143-5002
NSN 6150-00-078-7064
NSN 6610-01-394-3808
NSN 5925-01-170-5992
NSN 6130-01-177-6389
NSN 6685-00-960-4982
NSN 4140-00-276-9154
NSN 5960-01-487-6436