A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5935-01-454-2587
NSN 7035-01-444-9249
NSN 6620-00-827-1611
NSN 6620-01-070-9042
NSN 5965-00-042-5433
NSN 5945-01-579-4002
NSN 5998-01-654-8537
NSN 5998-01-584-4617
NSN 6320-01-415-0953
NSN 5905-00-846-8306
NSN 5920-01-396-2068
NSN 5996-00-648-6580