A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5935-01-567-3689
NSN 5950-01-250-2229
NSN 6150-00-686-8322
NSN 5835-01-436-6549
NSN 6135-01-285-8807
NSN 4140-01-476-2767
NSN 5996-01-472-2544
NSN 5835-01-632-6627
NSN 2925-00-936-9344
NSN 5990-01-482-5950
NSN 7035-01-240-0541
NSN 5855-01-105-7793