The Simpson Strong-Drive SDWS TIMBER Screw in 0.195 in. diameter by 7-1/2 in. length is a structural wood screw engineered for cross-laminated timber construction, mass timber assemblies, log-home construction, and general interior wood framing applications. Featuring a SawTooth point, serrated threads, and a low-profile washer head, this black E-coat electrocoated fastener is built to drive quickly and hold firmly in demanding wood-to-wood connections - including structural insulated panel (SIP) assemblies. Code listed under IAPMO-UES ER-192, it meets IRC and IBC code requirements for a wide range of common framing situations, making it a trusted choice for structural timber work.

Key Features

• SawTooth Point - starts fast and reduces installation torque, eliminating the need for predrilling in most interior timber applications and saving significant time on the job.
• Serrated Threads at 5 TPI with 3 in. thread length - cut aggressively into wood fibers to reduce splitting and material damage, especially valuable in dense mass timber and cross-laminated timber (CLT) construction.
• Low-profile washer head with 0.650 in. head diameter - provides maximum bearing area and pulls mating members tightly together without the need for additional washers, reducing hardware costs and installation steps.
• T40 6-lobe drive - delivers positive bit engagement that makes the screw easy to drive, reduces cam-out, and extends bit life during high-volume timber framing work.
• E-coat electrocoating finish - provides a uniform black coating that protects the fastener surface and suits interior structural applications where a clean, professional appearance matters.
• 0.195 in. shank diameter - offers a structural-grade cross-section that requires less torque to install than comparable larger-diameter lag screws, improving installer comfort and efficiency on long driving runs.
• Requires less torque than comparable fasteners - reduces fatigue during extended installation sessions and allows faster completion of structural timber connections without sacrificing holding strength.

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 precise thread engagement, reduced splitting, and code compliance are all essential at once.
• The large-diameter washer head eliminates the extra step of adding washers to achieve bearing area, simplifying installation and reducing the number of components needed on a timber framing project.
• Code listing under IAPMO-UES ER-192 with compliance to IRC and IBC requirements means this fastener can be specified and installed with confidence on permitted structural work - no guesswork about code acceptance.
• The combination of a SawTooth point and serrated threads means this screw can be driven without predrilling in most applications, cutting labor time significantly on large-scale log-home, SIP, or mass timber jobs.

Specifications

• Brand: Simpson Strong-Tie
• Shank Diameter (in.): 0.195
• Length (in.): 7 1/2
• Head Diameter (in.): 0.650
• Head Type: Low Profile Head
• Drive Type: T40 6-Lobe
• Thread Type: Serrated Threads
• Thread Length (in.): 3
• TPI: 5
• Point Type: SawTooth Point
• Coating: E-coat Electrocoating
• Finish: E-coat Electrocoating
• Color: Black
• Country of Origin: Taiwan

Available Pack Options

• SDWS19712-R50: 50 Pk - includes T40, 6-lobe driver bit (replacement bit: BIT40T-134-R2)
• SDWS19712: 250 Pk - includes T40, 6-lobe driver bit (replacement bit: BIT40T-134-R2)

Approved Applications

• Fastening Wood-to-Wood
• Log-Home Construction
• Structural Insulated Panels (SIPs)

Frequently Asked Questions

Do I need to predrill before installing this timber screw?

In most interior applications, predrilling is not required. The SawTooth point is specifically designed to ensure fast starts and reduce installation torque, allowing the screw to self-start in wood without a pilot hole in the majority of cross-laminated timber, mass timber, and general wood framing situations.

Is this screw rated for structural applications under building codes?

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 suitable for use on permitted structural interior timber projects.

What bit is needed to drive this screw, and is one included?

This screw uses a T40 6-lobe drive. A T40, 6-lobe driver bit is included with your order. If a replacement bit is needed, the replacement bit reference is BIT40T-134-R2.

Is this screw suitable for exterior or treated-lumber applications?

This screw features an E-coat electrocoating finish and is designed for interior applications - including cross-laminated timber construction, mass timber assemblies, log-home construction, and structural insulated panel (SIP) installations. For exterior or pressure-treated lumber environments, a different coating or corrosion rating should be verified against project requirements.