A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6150-01-461-7984
NSN 5920-01-265-7679
NSN 6105-01-384-6172
NSN 5895-01-204-3780
NSN 5835-01-259-0859
NSN 5920-00-296-9869
NSN 5930-00-185-6834
NSN 5920-01-512-8586
NSN 2925-01-519-1707
NSN 6610-01-646-8771
NSN 6610-01-062-9994
NSN 6220-01-631-0414