Simpson Strong-Drive SDWS Timber Screw - 0.220 in. diameter x 4 in. length is a structural wood screw engineered for cross-laminated timber construction, mass timber assemblies, log-home construction, and general interior wood-to-wood fastening applications. Finished in a black E-coat electrocoating, this interior-grade structural fastener drives faster and with less torque than comparable lag screws, making it a practical choice for demanding timber framing projects that require code-listed performance and reliable holding strength.

Key Features

• SawTooth Point - ensures fast starts and reduces installation torque, eliminating the need for predrilling in most applications so crews can work more efficiently on-site.
• Serrated Thread Design - reduces splitting and material damage during installation, protecting the integrity of cross-laminated and mass timber members.
• Low-Profile Washer Head (0.760 in. diameter) - provides maximum bearing area and pulls mating members together tightly without requiring extra washers, saving time and hardware costs.
• T40 6-Lobe Drive - delivers positive bit engagement for confident, controlled driving and extends bit life compared to standard hex or square drives.
• 0.220 in. Shank Diameter with 5-1/4 TPI Serrated Threads - offers strong thread purchase in dense timber materials while requiring less torque than comparable-diameter fasteners.
• E-coat Electrocoating Finish - provides a durable black corrosion-resistant surface suitable for interior structural applications including log-home and mass timber construction.
• Code Listed in IAPMO-UES ER-192 - meets 2018 and 2021 IRC and IBC requirements for most common wood framing applications, giving engineers and inspectors confidence in the fastener's structural rating.

Why This Product

• Engineered for modern timber construction methods - specifically designed for cross-laminated timber and mass timber assemblies, this screw addresses the unique demands of engineered wood products where splitting risk and torque requirements are critical concerns.
• Eliminates extra hardware steps - the large-diameter low-profile washer head pulls members down flush without the need for separate washers, reducing installation steps and material costs on large timber framing projects.
• Faster installs with less effort - the SawTooth point and serrated thread geometry require less torque than comparable lag screws, reducing installer fatigue on high-count fastening jobs like log-home construction or mass timber panels.
• Built-in code compliance - IAPMO-UES ER-192 listing and conformance with 2018 and 2021 IRC and IBC codes means this screw is accepted for most common structural wood framing applications, streamlining the permitting and inspection process.

Specifications

• Brand: Simpson Strong-Tie
• Shank Diameter (in.): 0.220
• Length (in.): 4
• Head Diameter (in.): 0.760
• Head Type: Low Profile Head
• Drive Type: T40 6-Lobe
• Thread Type: Serrated Threads
• Thread Length (in.): 2 3/8
• TPI: 5 1/4
• Point Type: SawTooth Point
• Coating: E-coat Electrocoating
• Finish: E-coat Electrocoating
• Color: Black

Available Pack Options

• SDWS22400-R50: 50 Pk - includes (1) T40, 6-lobe driver bit (replacement bit: BIT40T-134-R2)
• SDWS22400: 250 Pk - includes (2) T40, 6-lobe driver bits (replacement bit: BIT40T-134-R2)

Approved Applications

• Log-Home Construction
• Fastening Wood-to-Wood
• Cross-Laminated Timber Construction
• Mass Timber Construction
• General Interior Wood Framing Applications

Frequently Asked Questions

Does this screw require predrilling before installation?

In most applications, predrilling is not required. The SawTooth point is specifically designed to start fast and reduce installation torque, allowing the screw to self-start in timber and dimensional lumber without a pilot hole in the majority of common wood framing scenarios.

Is this screw suitable for outdoor or exterior applications?

This is an interior-grade screw finished with E-coat electrocoating. It is designed for interior structural applications including cross-laminated timber construction, mass timber assemblies, log-home construction, and general interior wood-to-wood fastening. For exterior or pressure-treated lumber applications, consult Simpson's exterior-rated SDWS product options.

What drive bit is required to install this screw?

This screw uses a T40 6-Lobe drive. A T40 driver bit is required for installation. The 6-lobe geometry provides positive engagement between the bit and the screw head, which reduces cam-out and extends bit life during high-volume driving.

What code listings does this screw carry?

This screw is code listed in IAPMO-UES ER-192 and meets the requirements of the 2018 and 2021 International Residential Code (IRC) and International Building Code (IBC) for most common wood framing applications, supporting use on permitted structural projects.