A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5910-01-197-4672
NSN 6320-01-397-0399
NSN 5960-01-282-2386
NSN 5998-01-590-2397
NSN 5965-00-760-5404
NSN 5925-01-555-7565
NSN 6620-00-266-2763
NSN 5975-01-421-3976
NSN 6110-01-232-6196
NSN 5998-01-279-9323
NSN 5925-00-353-0612
NSN 6105-00-251-7625