A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5985-00-529-0093
NSN 5950-00-960-9230
NSN 6135-00-416-2898
NSN 5999-01-010-5992
NSN 6130-00-446-6922
NSN 6105-01-181-4503
NSN 6685-01-388-6923
NSN 5930-01-313-2311
NSN 6320-01-116-3980
NSN 5945-01-252-8662
NSN 6320-01-280-5091
NSN 6110-00-136-9590