GRK RSS Structural Screw 5/16" x 5-1/8" T50 Star Drive

Engineered for heavy-duty wood framing and structural connections, the GRK RSS Structural Screw blends the strength of a lag screw with the ease of a self-drilling fastener. Featuring a T50 star drive and washer head, it delivers exceptional bit engagement and a smooth, flush finish—eliminating sharp edges and the need for pre-drilling in most applications. Whether you’re building decks, pergolas, or load-bearing wood assemblies, these screws offer consistent performance in both interior and intermittently wet exterior conditions.

Every screw is made from specially hardened steel and finished with GRK’s Climatek coating for superior corrosion resistance. Proprietary design elements like Zip-Tip and W-Cut threads ensure a low-effort installation, reduced splitting, and maximum draw into the substrate. CEE threads on the longer shank allow the wood to settle naturally, enhancing holding power while lowering driving torque.

Key Features

• T50 star drive for excellent bit retention and reduced cam-out
• Washer-type head with integrated shoulder for precise centering in hardware
• Zip-Tip point and W-Cut threads for self-drilling, self-tapping performance
• CEE threads on non-cutting shank reduce friction and improve draw
• Climatek corrosion-resistant coating for treated lumber and intermittent exterior use
• High tensile strength (4,247 lb) and shear strength (2,948 lb) for demanding structural loads
• Ideal for wood, hardwoods, deck framing, joist hangers, connector plates, and more