A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5935-01-257-5130
NSN 6130-01-573-8605
NSN 5925-00-759-8005
NSN 6610-01-655-7644
NSN 6610-00-125-8909
NSN 5996-01-068-9103
NSN 6620-01-456-0529
NSN 5930-00-548-9498
NSN 5996-00-456-0895
NSN 6135-00-958-7981
NSN 6150-01-384-5301
NSN 5835-00-138-7807