The Simpson Strong-Drive SDWS TIMBER Screw (0.220 in. diameter x 6 in. length, E-coat) is a structural wood screw engineered by Simpson for cross-laminated timber construction, mass timber assemblies, log-home construction, and general interior wood-to-wood fastening applications. The black E-coat electrocoating finish gives these fasteners a clean, low-profile appearance while providing corrosion resistance suited for interior environments. Designed to install faster and with less torque than comparable lag screws, the SDWS TIMBER screw is a go-to choice for timber framers, log-home builders, and structural contractors who need a reliable, code-listed fastener that drives cleanly without sacrificing holding power.

Key Features

• SawTooth point - starts fast and reduces installation torque, eliminating the need for predrilling in most wood-to-wood applications and saving significant time on large timber projects.
• Serrated thread design - reduces splitting and wood fiber damage during installation, protecting structural integrity in cross-laminated and mass timber assemblies.
• Low-profile washer head (0.760 in. diameter) with nibs - provides maximum bearing area and pulls timber members tight without requiring additional washers, simplifying installation and reducing material cost.
• T40 6-lobe drive - delivers positive bit engagement that keeps the driver centered under high torque, reducing cam-out and extending bit life on repetitive fastening tasks.
• 5-1/4 TPI with 3 in. thread length - optimized thread pitch draws members together efficiently, providing solid clamping force in thick timber sections.
• E-coat electrocoating finish in black - interior-grade corrosion resistance with a consistent, uniform black finish suited for exposed timber applications where appearance matters.
• 0.220 in. shank diameter - heavy-gauge structural shank handles the shear and withdrawal loads demanded by timber framing and log-home construction.
• Code listed under IAPMO-UES ER-192 - meets 2018 and 2021 IRC and IBC requirements for common wood framing applications, giving inspectors and engineers the documentation they need without additional engineering.
• Made in the United States - domestic manufacturing supports consistent quality control for structural fasteners used in code-listed applications.

Why This Product

• Engineered specifically for mass timber and cross-laminated timber (CLT) - the combination of SawTooth point, serrated threads, and large-diameter washer head addresses the unique challenges of fastening thick engineered wood members without predrilling or extra hardware.
• Reduces installation steps and materials - the built-in washer-style head eliminates the need for loose washers, and the low-torque SawTooth point removes the predrilling step in most applications, cutting labor time on high-volume timber framing jobs.
• Code compliance built in - IAPMO-UES ER-192 listing and IRC/IBC compliance mean these screws are accepted for structural connections in permitted construction, reducing back-and-forth with inspectors on residential and commercial timber projects.
• Includes the correct driver bit in the box - the T40 6-lobe bit is included, so installers are ready to drive immediately without sourcing a separate bit, which matters when working with a drive type not found in every standard bit set.

Specifications

• Brand: Simpson Strong-Tie
• Shank Diameter (in.): 0.220
• Length (in.): 6
• Head Diameter (in.): 0.760
• Head Type: Low Profile Head
• Drive Type: T40 6-Lobe
• Thread Type: Serrated Threads
• Thread Length (in.): 3
• TPI: 5 1/4
• Point Type: SawTooth Point
• Coating: E-coat Electrocoating
• Finish: E-coat Electrocoating
• Color: Black
• Country of Origin: United States

Available Pack Options

• SDWS22600-R50: 50 Pk - includes T40, 6-lobe driver bit (replacement bit: BIT40T-134-R2)
• SDWS22600: 250 Pk - includes T40, 6-lobe driver bit (replacement bit: BIT40T-134-R2)

Approved Applications

• Fastening Wood-to-Wood
• Log-Home Construction

Frequently Asked Questions

Does this screw require predrilling before installation?

In most applications, no. The SawTooth point is specifically designed to ensure fast starts and reduce installation torque, eliminating the need for predrilling in the majority of wood-to-wood fastening scenarios.

Is this screw suitable for outdoor or exposed exterior use?

No. This version of the Strong-Drive SDWS TIMBER screw features an E-coat electrocoating finish and is rated for interior applications. For exterior or treated-lumber environments, a different coating grade would be required.

What driver bit does this screw require, and is it included?

These screws use a T40 6-lobe drive. A T40 6-lobe driver bit is included in the box. If a replacement bit is needed, the compatible replacement is the BIT40T-134-R2.

Is this screw code listed for structural wood framing connections?

Yes. The Strong-Drive SDWS TIMBER screw is code listed under IAPMO-UES ER-192 and meets IRC and IBC code requirements for several common wood framing applications, making it accepted for use in permitted residential and commercial construction projects.