A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 4140-00-948-3663
NSN 6220-00-872-3032
NSN 5996-01-208-0472
NSN 5996-01-227-0767
NSN 6145-01-414-0271
NSN 5985-01-253-6851
NSN 6135-01-273-1253
NSN 6685-00-162-2052
NSN 2925-01-609-3525
NSN 6620-01-478-9667
NSN 6110-00-110-4265
NSN 5975-00-504-7792