GRK Black RSS (Rugged Structural Screw) Structural Screws are designed for strong, reliable wood-to-wood fastening in structural and construction applications. Featuring a black finish for a clean, professional appearance, these screws are ideal for visible wood connections. The 3-1/2" length is suitable for fastening framing members, posts, beams, and other wood components. Ideal for deck construction, timber framing, and general building projects, these screws provide a practical fastening solution for demanding applications. Follow the manufacturer's installation instructions for proper use.