A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5996-00-213-7121
NSN 5855-00-436-3852
NSN 6135-01-297-5565
NSN 5960-00-478-4337
NSN 5975-00-800-7477
NSN 5935-01-573-3755
NSN 6240-01-592-3176
NSN 5930-01-422-0537
NSN 5985-00-568-3726
NSN 5996-00-252-3495
NSN 5950-01-065-0858
NSN 5975-00-415-2049