A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5905-01-076-8092
NSN 6105-00-874-9364
NSN 6220-00-870-9967
NSN 5945-01-312-5411
NSN 6220-01-484-7067
NSN 5855-01-504-0645
NSN 5945-01-573-5746
NSN 5930-00-858-7431
NSN 7035-01-554-5540
NSN 6320-01-377-5701
NSN 5990-00-089-4340
NSN 6110-01-414-3500