A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6320-01-281-6028
NSN 5915-01-560-6795
NSN 6105-00-369-7700
NSN 5960-01-192-7710
NSN 6110-01-268-3021
NSN 5960-01-367-6153
NSN 5895-01-522-9583
NSN 7035-00-104-7613
NSN 5999-01-044-5832
NSN 2925-00-452-6403
NSN 6320-00-937-5625
NSN 6685-00-158-5584