A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5835-00-711-3371
NSN 5945-00-198-5499
NSN 6105-01-491-2045
NSN 6105-00-504-2822
NSN 6320-01-160-7757
NSN 5999-01-432-5240
NSN 4140-01-463-7952
NSN 5915-01-120-9173
NSN 5998-01-578-6316
NSN 5965-01-576-9859
NSN 5920-01-617-7320
NSN 5975-01-434-9054