A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5975-01-604-1311
NSN 5985-01-509-9095
NSN 5925-00-499-2160
NSN 5950-01-616-6343
NSN 5999-01-063-3160
NSN 5945-01-182-8121
NSN 5910-00-362-6687
NSN 6320-01-021-6633
NSN 5996-00-788-1218
NSN 6320-00-779-5923
NSN 5975-01-241-9230
NSN 6105-01-486-1456