5/16" x 4" Large Head Torx Lag Screws, Star Drive Truss Head Construction Lag Screws, Rust Resistant Ceramic Coated Bronze Self-Tapping Screws for Deck, Stair, Outdoor Wood Structure

Our 5/16" x 4" Large Head Torx Lag Screws are heavy-duty construction-grade fasteners engineered for demanding outdoor wood projects. Crafted from hardened steel with a multi-layer protective coating system—including metallic zinc layer, chemical barrier, and ceramic epoxy topcoat—these screws deliver exceptional rust and corrosion resistance, effectively repelling red rust and white rust to ensure long-term durability in harsh outdoor environments, such as decks, stairs, playsets, and other exterior wood structures.

Designed with a large truss head and Torx (star) drive system, these lag screws eliminate cam-out issues, enabling smooth, effortless driving every time. The Torx drive transfers torque more efficiently than traditional Phillips or square drives, drastically reducing bit slippage and head stripping, making installation faster and more reliable for both professional contractors and DIY enthusiasts. The optimized thread profile and sharp cutting point allow for direct installation without pre-drilling, significantly reducing labor time and project costs.

The large truss head design provides a wider bearing surface, distributing clamping force evenly to prevent pull-through and enhance structural stability, making it ideal for heavy-duty load-bearing applications. The bronze ceramic coated finish not only offers superior corrosion protection but also blends seamlessly with natural wood tones, maintaining a clean, professional appearance on outdoor structures.