A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5895-00-862-5564
NSN 5975-01-141-9353
NSN 5950-00-731-4946
NSN 5835-01-629-2044
NSN 5930-01-655-0849
NSN 5975-01-025-1870
NSN 6320-01-029-4220
NSN 6145-01-633-8796
NSN 5960-01-593-4760
NSN 5950-01-571-8560
NSN 5920-01-538-2269
NSN 4140-01-369-8109