A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6110-00-547-3230
NSN 6685-00-276-9889
NSN 7035-01-023-7859
NSN 6150-01-212-0604
NSN 6650-01-179-3823
NSN 5855-00-237-4088
NSN 5965-01-473-6082
NSN 5965-01-640-7104
NSN 5998-01-513-0864
NSN 6135-01-468-6491
NSN 6110-00-675-0101
NSN 5998-00-269-3775