The Simpson Strong-Drive SDWS Timber Screw with Double-Barrier Coating is a heavy-duty structural fastener engineered to deliver a high-strength, easy-to-install alternative to through-bolting and traditional lag screws in wood-to-wood connections. Featuring a 0.220 in. shank diameter, 10 in. length, and a black double-barrier coating that provides corrosion resistance equivalent to hot-dip galvanization, this structural wood screw is suited for a wide range of framing, crating, and exterior timber applications. Code listed in IAPMO UES ER-192 and meeting IRC and IBC requirements for most common wood framing applications, it is a trusted choice for contractors and do-it-yourselfers working with pressure-treated and exterior lumber.

Key Features

• SawTooth Point - enables fast starts and reduces installation torque, eliminating the need for predrilling in most applications and saving significant time on the job site.
• T40 6-Lobe Drive Type - provides positive bit engagement during driving, which improves bit life and gives the installer better control with less cam-out compared to standard drive types.
• Washer Head with 0.760 in. Head Diameter - delivers a large bearing surface area that distributes load evenly across the wood face, reducing the risk of pull-through in structural timber connections.
• Double-Barrier Coating (Black) - offers corrosion resistance equivalent to hot-dip galvanization, making this screw suitable for certain exterior conditions and preservative-treated wood applications where long-term durability is required.
• 5 TPI Thread with 3 in. Thread Length - the aggressive low-pitch thread is designed for maximum holding power in heavy timber and dimensional lumber, resisting withdrawal forces in structural framing connections.
• Code Listed in IAPMO UES ER-192 - meets IRC and IBC requirements for most common wood framing applications, so installers can use this fastener with confidence on permitted, inspected projects.
• T40 Driver Bit Included - the correctly sized driver bit comes in the package, so installers can start immediately without sourcing additional tooling.

Why This Product

• Replaces through-bolts and lag screws - the SDWS Timber Screw installs with a standard drill rather than requiring pre-boring, drilling, and bolt hardware, significantly reducing labor time and complexity on structural wood-to-wood connections.
• Corrosion resistance for demanding environments - the double-barrier coating matches the protection level of hot-dip galvanization, making this screw a practical option for exterior framing and certain preservative-treated lumber applications where fastener degradation is a real concern.
• Verified for code-compliant framing - with IAPMO UES ER-192 code listing and compliance with IRC and IBC requirements, this fastener supports projects that require documented, inspectable structural connections.
• Suitable for contractors and DIY users alike - the SawTooth point, included driver bit, and low-speed drill compatibility make this screw accessible and practical for a wide range of skill levels and jobsite conditions.

Specifications

• Brand: Simpson Strong-Tie
• Shank Diameter (in.): 0.220
• Length (in.): 10
• Head Diameter (in.): 0.760
• Head Type: Washer Head
• Drive Type: T40 6-Lobe
• Point Type: SawTooth Point
• Thread Length (in.): 3
• TPI: 5
• Coating: Double-Barrier Coating
• Finish: Double-Barrier Coating
• Color: Black
• Country of Origin: Taiwan

Available Pack Options

• SDWS221000DBBR50: 50 Pk - includes 6-lobe, T40 driver bit
• SDWS221000DBB: 250 Pk - includes 6-lobe, T40 driver bit

Approved Applications

• Fastening Wood-to-Wood
• Crating

Install With

• SDWS screws install best with a low-speed 1/2 in. drill and 6-lobe, T40 driver bit (bit included)

Frequently Asked Questions

Does this screw require predrilling before installation?

In most applications, predrilling is not required. The SawTooth point is specifically designed to ensure fast starts and reduce installation torque, allowing the screw to seat directly into wood without a pilot hole in most common framing scenarios.

Is this screw suitable for use with pressure-treated lumber?

Yes. The double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization, making this screw suitable for certain exterior and preservative-treated wood applications as described in the IAPMO UES ER-192 evaluation report.

What type of drill is recommended for driving this screw?

These screws install best with a low-speed 1/2 in. drill paired with the 6-lobe T40 driver bit. A T40 driver bit is included, so no additional tooling needs to be sourced before installation.

Is this fastener approved for use on permitted construction projects?

Yes. The SDWS Timber Screw is code listed in IAPMO UES ER-192 and meets IRC and IBC requirements for most common wood framing applications, making it appropriate for use on projects subject to building code inspection.