Simpson Strong-Drive SDWH TIMBER-HEX Stainless Steel Screw (0.275" x 4") by Simpson is a structural hex-head fastener engineered as a direct replacement for traditional lag screws in wood-framing and ledger applications. Constructed from Type 316 stainless steel, this heavy-duty structural screw delivers maximum corrosion resistance in demanding outdoor, coastal, and chemically exposed environments - making it a reliable choice wherever long-term fastener integrity is critical. Its no-predrill design speeds up installation and reduces labor time compared to conventional lag screws, and it meets 2018 and 2021 IRC and IBC code requirements for several common wood-framing applications.

Key Features

• Type 316 stainless steel material and finish - provides superior corrosion resistance in saltwater, coastal, and chemically aggressive environments where standard zinc-plated fasteners would fail prematurely.
• No predrilling required in most applications - saves significant installation time and eliminates the extra step required with traditional lag screws, reducing labor costs on framing projects.
• Sharp point tip - starts cleanly and drives directly into wood without pilot holes, making one-handed fastener placement faster and more consistent in the field.
• Hex washer head (0.655 in. head diameter) - creates a large bearing surface that distributes clamping force across a wider area, reducing the risk of pull-through in structural connections.
• 1/2 in. hex drive type - compatible with standard hex-socket impact drivers and wrenches, enabling high-torque installation without cam-out.
• Box thread design with 7 TPI and 3 in. thread length - raised-ridge thread technology significantly reduces driving torque, making this screw easier to drive while still achieving strong pull-out values in timber connections.
• Meets 2018 and 2021 IRC and IBC code requirements - provides documented compliance for structural wood-framing applications, simplifying inspection and permitting on job sites.
• Driver bit included - means you can begin installation immediately without sourcing a separate bit, keeping projects moving without interruption.

Why This Product

• True lag-screw replacement without the extra steps - traditional lag screws require predrilling, adding time and tools to every connection point. This structural screw drives directly into wood, cutting installation steps while still meeting the same structural demands.
• Built for environments where corrosion is a real threat - Type 316 stainless steel is the appropriate material choice for outdoor decks, dock framing, coastal construction, and applications involving pressure-treated lumber where lesser finishes degrade quickly.
• Code-compliant for residential and commercial framing - compliance with 2018 and 2021 IRC and IBC requirements means this fastener can be specified with confidence in permitted structural framing work, including ledger connections.
• Engineered thread geometry reduces installation effort - the box thread design with raised-ridge technology lowers driving torque, which reduces driver fatigue and wear on tools during high-volume structural fastening tasks.

Specifications

• Brand: Simpson Strong-Tie
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Length (in.): 4
• Shank Diameter (in.): 0.275
• Head Diameter (in.): 0.655
• Head Type: Hex Washer Head
• Drive Type: 1/2 in. Hex
• Thread Type: Box Threads
• Thread Length (in.): 3
• TPI: 7
• Point Type: Sharp Point
• Country of Origin: Taiwan

Available Pack Options

• SDWH27400SS-R10: 10 Pk - includes (1) driver bit
• SDWH27400SS-R100: 100 Pk - includes (1) driver bit

Frequently Asked Questions

Do these screws require predrilling before installation?

No. The Simpson Strong-Drive SDWH TIMBER-HEX screws are designed to require no predrilling in most applications. The sharp point and box thread geometry allow the fastener to drive directly into wood, making installation faster and simpler than traditional lag screws.

What type of drive tool is needed to install these screws?

These screws use a 1/2 in. hex drive and are installed with a standard hex-socket driver or impact wrench. A driver bit is included with your purchase so you can begin installation right away.

Are these screws approved for use in ledger board connections?

Yes. The Strong-Drive SDWH TIMBER-HEX screws can be used in ledger applications and meet 2018 and 2021 IRC and IBC code requirements for several common wood-framing applications, supporting use in both residential and commercial permitted construction.

Why is Type 316 stainless steel specified for these structural screws?

Type 316 stainless steel offers a higher level of corrosion resistance than standard stainless grades, making it well-suited for outdoor wood-framing, coastal environments, and applications involving pressure-treated lumber where moisture and chemicals can degrade lesser materials over time.

Note: Product dimensions and/or thread length may differ from picture.