A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5998-00-400-1257
NSN 5895-01-383-6999
NSN 5985-01-244-5360
NSN 6645-01-233-1131
NSN 5945-01-624-4922
NSN 4140-00-564-5986
NSN 6240-00-527-8614
NSN 6620-01-024-1228
NSN 5990-00-242-3754
NSN 5895-01-217-7657
NSN 5965-00-144-2543
NSN 6150-01-484-9299