A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5965-01-198-3256
NSN 5945-00-470-7446
NSN 5945-01-207-1732
NSN 4140-00-305-1023
NSN 7035-01-395-0757
NSN 5930-01-414-3889
NSN 6685-00-861-5445
NSN 5998-01-257-9236
NSN 6645-01-470-6838
NSN 6110-01-168-8600
NSN 5945-00-470-2584
NSN 6145-01-003-9741