A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6130-01-369-6817
NSN 6135-01-415-1163
NSN 5965-01-271-0808
NSN 5945-01-571-8594
NSN 5935-01-041-2020
NSN 5945-01-614-5548
NSN 6620-01-415-5803
NSN 5925-01-624-8671
NSN 5925-00-198-3689
NSN 5990-01-376-8930
NSN 5935-01-529-7868
NSN 5915-01-474-1937