A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6135-01-612-5578
NSN 7035-01-227-7492
NSN 5950-00-121-9165
NSN 5945-00-104-8097
NSN 5895-00-961-0031
NSN 6150-01-564-9709
NSN 5930-00-679-9076
NSN 5855-00-466-2309
NSN 5925-01-552-5515
NSN 4140-00-008-4912
NSN 5950-01-380-4641
NSN 6105-00-590-4424