A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5835-01-299-5055
NSN 4140-00-045-8117
NSN 6685-01-265-8724
NSN 6145-01-200-7075
NSN 6105-01-588-9129
NSN 5835-01-152-9483
NSN 6150-00-246-6673
NSN 5998-01-104-4783
NSN 7035-01-501-9118
NSN 6320-01-652-3806
NSN 5935-01-513-8032
NSN 6620-01-424-6925