5/8-18 Castle Nut Grade 5 Zinc (Pack Qty 150) BC-63NHC5

Low Carbon Steel: The Slotteds are for the insertion of a cotter pin to secure the nut when used with a drilled shank fastener. The Slottedted and castle styles are both interchangeable with the Slottedted design now the preferred style. Grade-5: Offers same advantages as the low carbon castle nut but can be used with Grade-5 bolts and cap screws Low Carbon Steel: Nuts shall be made from a low-carbon steel which conforms to the following chemical composition requirements Carbon: 0.47% max.; Phosphorus: 0.12% max.; Sulfur: 0.23% max. Rockwell C32 maximum