A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5930-01-223-2996
NSN 6650-01-159-7961
NSN 5905-01-511-6605
NSN 6650-00-650-8080
NSN 6240-00-185-8367
NSN 6645-00-736-0476
NSN 6105-00-758-0610
NSN 6105-01-241-9936
NSN 5965-01-515-8461
NSN 6110-00-129-8714
NSN 6150-00-338-8953
NSN 5945-01-228-3923