Hex Head Lag Screw, Material 18-8 Stainless Steel, Finish Plain, Screw Size 5/16 In., Fastener Length 4 in, Threads per Inch 9, Thread Style Partially Threaded, Minimum Thread Length 2 1/2 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 10