A bent spring metal washer with a centrally located hole. It is designed to exert pressure axially when assembled in place.
NSN 6240-01-530-6769
NSN 6645-00-522-4173
NSN 5855-01-594-7809
NSN 6645-00-837-2267
NSN 5895-00-055-6381
NSN 5960-00-985-0262
NSN 5910-01-251-9592
NSN 6620-01-286-6769
NSN 5895-00-292-2872
NSN 5998-01-446-6333
NSN 5895-01-457-3702
NSN 5996-00-856-4762