A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 5960-01-640-6473
NSN 6145-00-615-2019
NSN 6610-00-585-4366
NSN 5935-01-090-6406
NSN 5965-00-836-2690
NSN 5965-00-553-6898
NSN 5945-00-448-2784
NSN 6620-00-624-7169
NSN 5910-01-352-8886
NSN 6240-00-643-4532
NSN 5855-01-061-6890
NSN 6145-00-343-5967