GRK Black RSS (Rugged Structural Screw) Structural Screws are designed for secure wood-to-wood fastening in structural and construction applications. Featuring a black finish for a clean, professional appearance, these screws are ideal for exposed wood connections. The 4" length is suitable for fastening framing members, beams, posts, and other wood components in deck construction, timber framing, and general building projects. Designed for demanding fastening applications, GRK RSS screws offer a practical alternative to traditional lag screws where appropriate. Follow the manufacturer's installation instructions for proper use.