Hex Head Lag Screws Material Steel Finish Zinc Plated Screw Size 5/16 in Fastener Length 4 1/2 in Threads per Inch 9 Thread Style Partially Threaded Minimum Thread Length 3 29/64 in Dimensional Standards ASME B18.2.1 Pack Size Small 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 50