1/2 x 4 1/2 Hex Lag Screw Hot Dipped Galvanized .Hex Lag Screws are manufactured from low carbon steel to meet SAE J429 Grade 1.Lag screws longer than 12 inches will have a minimum thread length of 50% of the screw length up to a maximum of 8 inches.Zinc plated material will meet or exceed ASTM F1941.Hot-Dip Galvanized material will meet or exceed ASTM A153.Typical hardness is HRB 70-100.Tensile strength (not pull out) will meet a minimum of 60,000 psi.