GRK Fasteners RSS 5/16 x 3-1/8 Inch, Black Multi-Purpose Structural Screws, 100 PCS, Rust Resistant Climatek Coating, Decorative Hardware Decking Screws, Star Drive Recess, T-30 Bit Included, Black

Heavy Duty Lag Screw Alternative: Eliminates pre-drilling in most woods with Zip-Tip technology. Installs 3x faster than traditional lag screws | ESR-2442 Code Approved For Structural Applications: Engineered for professional-grade connections in heavy duty framing, multi-ply beams, and timber framing. Integrated washer head delivers maximum clamping force for zero-gap joints in LVL, LSL, and engineered lumber. | Advanced Corrosion Protection: Rust resistant Black Climatek coating provides exceptional durability for outdoor use and in pressure-treated lumber applications while matching decorative hardware | W-cut Thread Design: Reduces installation torque by 40% for smoother, faster driving. CEE threads minimize splitting in dense hardwoods, engineered lumber, and laminated beams. | Precision Engineering: Star/Torx drive recess with 6 points of contact prevents stripping and minimizes wobble between screws and bits.