GRK RSS Rugged Structural Screw is a structural fastener designed for ease of installation and the strongest of connections. With proprietary features like the Zip-Tip, and W-Cut thread, RSS fasteners drive into most woods without the need for pre-drilling. The specially engineered design results in a low-effort installation, especially compared to conventional lag screws. RSS Rugged Structural Screws have a Climatek Coating for installation in both interior and exterior conditions where exposure to moisture is intermittent and is code-approved for use in treated lumber.