Back Home / Fasteners / Nuts / HEX NUT UNF ZINC 5/8″-18 GR 5 HEX NUT UNF ZINC 5/8″-18 GR 5 SKU: N5818 Categories: Fasteners, Nuts A finished hex nut made from low carbon steel. For use with grade 5 bolts. Proof load: 109,000 psi. Size: 5/8″-18. Zinc plated. A finished hex nut made from low carbon steel. For use with grade 5 bolts. Proof load: 109,000 psi. Size: 5/8″-18. Zinc plated. Case Quantity: 25 Log In For Pricing