A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5960-01-276-7836
NSN 5996-01-065-3440
NSN 4140-01-288-0512
NSN 5990-00-518-0684
NSN 6150-01-136-5975
NSN 5920-01-345-5433
NSN 5920-01-381-4563
NSN 6105-00-841-5202
NSN 5985-01-316-2007
NSN 5915-01-378-6058
NSN 7035-01-027-2259
NSN 5996-01-542-4150