A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5930-01-352-5428
NSN 6620-00-820-9616
NSN 5835-01-580-0446
NSN 5945-01-254-4403
NSN 6685-01-152-7303
NSN 5930-01-353-7821
NSN 4140-01-378-0903
NSN 5960-00-723-2793
NSN 5935-01-103-5984
NSN 6610-00-647-3830
NSN 7035-01-555-8289
NSN 6220-01-656-8658