A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5835-00-074-3700
NSN 6610-01-109-5105
NSN 5930-01-273-0775
NSN 6650-00-089-9423
NSN 6645-01-438-6986
NSN 2925-00-245-4440
NSN 5910-01-317-9951
NSN 6645-01-159-8787
NSN 5855-01-244-9785
NSN 6240-00-455-7640
NSN 5915-01-031-1510
NSN 6610-00-527-8892