The Simpson Strong-Tie® Strong-Drive® SDWS™ Timber screw is designed to provide an easy-to-install, high-strength alternative to through-bolting and traditional lag screws. This screw is ideal for the contractor and do-it-yourselfer alike. It is code listed in IAPMO UES ER-192 and meets IRC® and IBC® code requirements for most common wood framing applications. The double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization, making it suitable for certain exterior and preservative-treated wood applications, as described in the evaluation report. Strong-Drive® SDWS™ TIMBER Screw (Exterior Grade) — 0.220 in. x 6 in. T40, Tan (Pack of 19840).