Hex Head Lag Screw, Material Steel, Finish Hot Dipped Galvanized, Screw Size 5/16 In., Fastener Length 4 in, Dimensional Standards ASME B18.2.1, Pack Size Bulk, System of Measurement Inch, Drive External Hex, Drive Size 1/2 in, Head Height 0.219 in, Head Style Hex, Head Width 0.324 in, Package Quantity 350