A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6110-01-250-9167
NSN 6150-01-176-4909
NSN 5965-01-512-8842
NSN 5925-00-523-9158
NSN 6220-01-027-1294
NSN 6685-01-240-5895
NSN 4140-01-146-4474
NSN 5960-01-273-0942
NSN 5855-01-341-2518
NSN 5990-00-855-9451
NSN 5895-01-462-5271
NSN 5835-01-237-3769