The Simpson Strong-Drive SDWS Timber Screw - 0.220 in. diameter x 12 in. length, E-coat finish is a heavy-duty structural wood fastener engineered for cross-laminated timber construction, mass timber assemblies, log-home construction, and general interior wood-to-wood applications. Built by Simpson, this black E-coat electrocoated screw delivers the holding power and code-compliance professionals demand, while requiring less torque to install than comparable structural lag screws - making it a practical choice for high-volume timber framing projects.

Key Features

• SawTooth Point - starts fast, reduces installation torque, and eliminates the need to predrill in most timber applications, saving time on the job site.
• Serrated Threads at 5-1/4 TPI with a 3 in. thread length - reduces wood splitting and surface damage as the screw draws members together, protecting the integrity of the timber assembly.
• Low-Profile Washer Head (0.760 in. diameter) - large bearing area pulls members tight without extra washers, streamlining installation and reducing hardware costs.
• T40 6-Lobe Drive - provides positive bit engagement that reduces cam-out, extends bit life, and makes driving 12 in. screws more controlled and efficient.
• E-coat Electrocoating Finish - uniform black coating provides corrosion resistance appropriate for interior applications while giving the fastener a clean, finished appearance.
• 0.220 in. Shank Diameter - larger structural shank delivers high shear and withdrawal values suited for demanding mass timber and cross-laminated timber connections.
• Code Listed - IAPMO-UES ER-192 - meets 2018 and 2021 IRC and IBC code requirements for common wood framing applications, supporting permit-ready project documentation.

Why This Product

• Designed specifically for cross-laminated timber and mass timber construction, this screw addresses the unique demands of modern engineered wood assemblies where structural integrity and code compliance are non-negotiable.
• The combination of the SawTooth point and serrated thread means less torque needed to drive a full 12 in. screw compared to standard lag screws - reducing installer fatigue and speeding up production in log-home and heavy timber framing.
• The large low-profile washer head eliminates the need for separate washers in wood-to-wood connections, reducing parts count and simplifying the fastening process on timber projects.
• IAPMO-UES ER-192 code listing ensures these structural fasteners meet IRC and IBC requirements, giving contractors and inspectors confidence in the connection for permitted interior timber framing applications.

Specifications

• Brand: Simpson Strong-Tie
• Shank Diameter (in.): 0.220
• Length (in.): 12
• 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

Available Pack Options

• SDWS221200-R50: 50 Pk - includes T40, 6-lobe driver bit (replacement bit: BIT40T-134-R2)
• SDWS221200: 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

Is this screw suitable for exterior or outdoor applications?

No. This screw features an E-coat Electrocoating finish and is rated for interior applications only. For exterior or pressure-treated lumber applications, a different corrosion-protection coating would be required. Always match the fastener finish to the environmental exposure conditions of your project.

Do I need to predrill before installing this screw in timber?

In most applications, predrilling is not required. The SawTooth point is specifically designed to start fast and reduce installation torque, allowing the screw to be driven without a pilot hole in the majority of interior timber and wood-to-wood connections.

What drive bit does this screw use, and is one included?

This screw uses a T40 6-lobe drive, and a T40 6-lobe driver bit is included with the product. If you need a replacement bit, the compatible part is the BIT40T-134-R2.

Is this screw code-listed for structural timber framing?

Yes. This fastener is code listed under IAPMO-UES ER-192 and meets 2018 and 2021 IRC and IBC code requirements for several common wood framing applications, including cross-laminated timber and mass timber construction.