A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6620-00-838-6954
NSN 5895-01-183-8114
NSN 5835-01-141-4975
NSN 6145-01-541-9085
NSN 6150-01-090-6691
NSN 5925-01-509-2128
NSN 6320-01-064-0372
NSN 5925-01-499-3815
NSN 5925-01-078-2374
NSN 6110-01-588-1058
NSN 5915-01-494-5692
NSN 5996-00-403-3753