A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5945-01-062-9281
NSN 5965-00-265-7861
NSN 5960-01-171-8944
NSN 6105-01-438-5846
NSN 5965-01-640-7104
NSN 6220-00-939-8609
NSN 5999-01-343-5165
NSN 5835-01-432-1277
NSN 5945-01-480-1777
NSN 6145-01-354-8806
NSN 6320-00-841-2279
NSN 5998-01-398-8930