A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5965-00-300-8055
NSN 5998-01-030-6427
NSN 6150-00-998-8270
NSN 2925-01-361-5310
NSN 5998-01-625-5383
NSN 5985-01-386-1605
NSN 6130-01-551-2560
NSN 5930-01-631-7201
NSN 5965-01-217-7167
NSN 5999-01-309-2393
NSN 5915-00-846-7632
NSN 7035-01-540-4360