A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5855-01-147-4785
NSN 6150-01-513-6213
NSN 6620-00-816-9755
NSN 6135-01-391-6515
NSN 5950-00-854-7363
NSN 6620-01-476-7355
NSN 5985-00-394-5888
NSN 6150-01-015-9910
NSN 7035-00-574-4223
NSN 5945-01-640-7097
NSN 5835-01-156-5622
NSN 4140-00-242-3574