A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5915-01-438-6185
NSN 5996-01-485-0305
NSN 6620-01-463-1373
NSN 5930-01-321-4394
NSN 7035-01-559-8218
NSN 5975-00-118-8771
NSN 5920-01-658-8794
NSN 5975-00-817-1781
NSN 5990-01-118-8624
NSN 7035-00-997-6212
NSN 5990-01-122-9149
NSN 7035-00-064-7008