A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5920-00-189-0858
NSN 6240-01-259-4015
NSN 5920-00-855-5314
NSN 6320-01-352-5653
NSN 5855-01-147-6024
NSN 5975-01-307-6656
NSN 6685-01-151-7106
NSN 5930-01-238-6850
NSN 5895-00-435-8209
NSN 6650-00-997-4337
NSN 6240-00-295-2729
NSN 5960-01-408-7692