5/16 x 3-1/8" Rugged-Structural-Screw

Easy to install lag alternative. Zero stripping recessed star drive. Cee thread for a clean finished look W-Cut for low torque, smoother drive. ZIP-TIP for no pre-drilling, faster penetration. Washer head provides immense holding power. Cutting pockets provide a clean hole, reduces splitting, and bore with precision. ESR-3201 Approved for structural application. Case Hardened steel for high tensile, torque and shear strength. Climatek Coated: AC257 code approved for use in treated lumber. For interior/exterior use in: carrying beams, ledger boards, stair rails, deck posts, playground equipment and other professional applications.