A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6135-00-297-8873
NSN 6240-01-657-6037
NSN 6650-01-228-5094
NSN 6240-01-228-6289
NSN 5990-01-645-2592
NSN 6145-00-936-0083
NSN 6150-01-440-2061
NSN 5855-00-962-5792
NSN 5960-01-392-6982
NSN 5945-00-237-4879
NSN 5999-01-434-9005
NSN 6150-01-381-7168