The Simpson Strong-Drive SDWS Timber Screw is a high-strength, heavy-duty structural fastener engineered to deliver a fast, code-compliant alternative to traditional lag screws and through-bolting in wood framing and timber construction. Built with a 0.220-inch shank diameter, a 6-inch length, and a double-barrier coating that provides corrosion resistance equivalent to hot-dip galvanization, this screw is purpose-built for demanding wood-to-wood fastening tasks where reliability and long-term performance in exterior and preservative-treated wood environments are critical. Whether you are a professional contractor or a dedicated do-it-yourselfer, this T40 6-lobe driven washer-head screw simplifies structural fastening without sacrificing strength or code compliance.

Key Features

• SawTooth Point - ensures fast, accurate starts and significantly reduces installation torque, eliminating the need for predrilling in most wood framing applications and saving time on the job site.
• Bold thread design with 5 TPI - delivers superior holding power in wood-to-wood connections, giving each fastener exceptional withdrawal resistance in structural applications.
• Washer head with 0.760-inch head diameter - provides a large bearing area that distributes load across the wood surface, reducing the risk of pull-through and improving connection performance.
• Underhead nibs - allow the head to drive flush to the surface with reduced splintering, resulting in a cleaner, more professional finish on framing and timber connections.
• T40 6-lobe drive - provides positive bit engagement that makes the screw easier to drive, reduces cam-out, and extends driver bit life compared to traditional hex or Phillips drives.
• Double-barrier coating - provides corrosion resistance equivalent to hot-dip galvanization, making these timber screws suitable for certain exterior applications and use with preservative-treated wood as described in the evaluation report.
• 3-inch thread length on a 6-inch shank - concentrates thread engagement where it matters most, optimizing pull-out strength while the unthreaded shank draws connected members tightly together.
• Code listed in IAPMO UES ER-192 - meets IRC and IBC code requirements for most common wood framing applications, simplifying inspections and providing confidence in code-compliant structural connections.
• Size identification on screw head - makes it easy to identify the correct fastener on the job site, reducing installation errors when working with multiple screw sizes.

Why This Product

• A direct, stronger replacement for lag screws and through-bolts - the SDWS Timber Screw is specifically designed to replace traditional lag screws and through-bolting methods in wood framing, offering equivalent or superior structural performance with dramatically faster installation and no need for predrilling in most applications.
• Proven corrosion protection for exterior and treated-wood use - the double-barrier coating delivers corrosion resistance equivalent to hot-dip galvanization, making this screw a reliable choice for outdoor structural connections and applications involving preservative-treated lumber where long-term durability matters.
• Designed for both professionals and DIYers - the SawTooth point, large washer head, and T40 6-lobe drive work together to make installation straightforward and efficient without sacrificing structural integrity, reducing labor time whether on a commercial framing project or a residential deck build.
• Code compliance built in - with code listing under IAPMO UES ER-192 and compliance with IRC and IBC requirements for most common wood framing applications, these screws take the guesswork out of meeting inspection standards on regulated construction projects.

Specifications

• Brand: Simpson Strong-Tie
• Shank Diameter: 0.220 in.
• Length: 6 in.
• Head Diameter: 0.760 in.
• Head Type: Washer Head
• Drive Type: T40 6-Lobe
• Point Type: SawTooth Point
• Thread Length: 3 in.
• TPI: 5
• Coating/Finish: Double-Barrier Coating
• Color: Black
• Code Listing: IAPMO UES ER-192; meets IRC and IBC code requirements for most common wood framing applications
• Country of Origin: Taiwan

Available Pack Options

• SDWS22600DBB-R50: 50 Pk - includes one 6-lobe, T40 driver bit
• SDWS22600DBBMB: 250 Pk - includes one 6-lobe, T40 driver bit
• SDWS22600DBB: 500 Pk - includes two 6-lobe, T40 driver bits

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 (included)

Frequently Asked Questions

Do I need to predrill before installing the SDWS Timber Screw?

In most applications, predrilling is not required. The SawTooth point is designed to ensure fast starts and reduce installation torque, allowing the screw to self-start in most wood framing situations without the need for a pilot hole.

Is the double-barrier coating suitable for use with pressure-treated lumber?

Yes. 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 IAPMO UES ER-192 evaluation report.

What driver bit is needed to install these screws?

A T40 6-lobe driver bit is required. For best results, use a low-speed 1/2-in. drill with a compatible T40 6-lobe driver bit. The positive engagement of the 6-lobe drive reduces cam-out and helps extend bit life.

Are these screws code approved for structural wood framing?

Yes. The Strong-Drive SDWS Timber Screw is code listed under IAPMO UES ER-192 and meets IRC and IBC code requirements for most common wood framing applications, making it suitable for regulated residential and commercial construction projects.