A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6135-01-204-8712
NSN 5960-01-613-6122
NSN 6240-01-347-0072
NSN 6135-01-412-0404
NSN 6220-01-336-7414
NSN 7035-00-679-9027
NSN 5985-01-178-0316
NSN 5915-01-279-5875
NSN 6145-00-797-3454
NSN 6685-01-521-4715
NSN 5895-01-610-0383
NSN 6135-01-563-4445