The Simpson Strong-Drive SDWH Timber-Hex Screw with Double-Barrier Coating is a heavy-duty structural fastener engineered for wood-to-wood connections and general-purpose framing where a hex-head drive delivers reliable torque and control. Featuring a 5/16 in. hex drive and large hex washer head, this 0.195 in. x 4 in. timber screw is equally at home in the hands of professional contractors and experienced do-it-yourselfers. Code listed under IAPMO-UES ER-192 and compliant with both 2015 and 2018 IRC and IBC requirements, it brings verified performance to structural wood framing applications where compliance matters.

Key Features

• Double-Barrier Coating - provides a corrosion-resistant finish equivalent to hot-dip galvanization, making it suitable for demanding exterior and preservative-treated wood environments where standard fasteners fall short.
• SawTooth Point - cuts cleanly into wood fiber on contact, eliminating the need for pre-drilling and saving significant time compared to traditional lag bolts, especially in repetitive structural fastening tasks.
• 5/16 in. Hex Drive with Large Hex Washer Head (0.650 in. diameter) - delivers high torque transfer and a wide bearing surface, reducing the chance of fastener pull-through and keeping the connection tight under load.
• 4 in. Length with 2-3/8 in. Thread Length - provides deep thread engagement into the receiving member for solid structural holding power in wood-to-wood assemblies.
• 6 TPI (Threads Per Inch) Coarse Thread Pattern - optimized for wood fastening, pulling members together efficiently and resisting loosening over time in structural applications.
• IAPMO-UES ER-192 Code Listed - meets 2015 and 2018 IRC and IBC code requirements, giving contractors documented compliance for inspections without additional engineering sign-off for listed applications.
• 0.195 in. Shank Diameter - a robust shank that resists shear forces in structural connections, providing reliable performance where strength is critical.

Why This Product

• The SawTooth point eliminates pre-drilling entirely, which directly reduces labor time on structural wood framing projects - a measurable advantage on any job site where productivity matters.
• The Double-Barrier Coating provides corrosion resistance comparable to hot-dip galvanization, making these timber screws a dependable choice for exterior structural connections and applications involving preservative-treated lumber.
• Code listing under IAPMO-UES ER-192 with compliance to both 2015 and 2018 IRC and IBC standards means inspectors and contractors can reference a recognized standard, reducing the paperwork burden on common wood framing jobs.
• The large hex washer head combined with the 5/16 in. hex drive makes this screw compatible with standard impact drivers and hex-drive bits, fitting naturally into existing tool setups without specialized equipment.

Specifications

• Brand: Simpson Strong-Tie
• Length (in.): 4
• Shank Diameter (in.): 0.195
• Head Diameter (in.): 0.650
• Head Type: Large Hex Washer Head
• Drive Type: 5/16 in. Hex
• Thread Length (in.): 2 3/8
• TPI: 6
• Point Type: SawTooth Point
• Coating/Finish: Double-Barrier Coating
• Country of Origin: Taiwan

Available Pack Options

• SDWH19400DB-RP1: 3 Pk
• SDWH19400DB-R12: 12 Pk - includes one 5/16-in. hex driver bit
• SDWH19400DB-R50: 50 Pk - includes one 5/16-in. hex driver bit
• SDWH19400DBMB: 250 Pk - includes one 5/16-in. hex driver bit
• SDWH19400DB: 800 Pk - includes two 5/16-in. hex driver bits

Approved Applications

• Fastening Wood-to-Wood
• Crating

Frequently Asked Questions

Do these timber screws require pre-drilling before installation?

No. The SawTooth Point is specifically designed to cut into wood on contact, eliminating the need for pre-drilling. This makes installation faster compared to traditional lag bolts, particularly in repetitive wood-to-wood fastening tasks.

What code compliance does this screw carry?

The Strong-Drive SDWH Timber-Hex Screw is code listed under IAPMO-UES ER-192 and meets the requirements of both the 2015 and 2018 IRC (International Residential Code) and IBC (International Building Code) for several common wood framing applications.

Is the Double-Barrier Coating suitable for use with pressure-treated lumber?

The Double-Barrier Coating provides corrosion resistance comparable to hot-dip galvanization, making these screws suitable for some exterior and preservative-treated wood applications. For project-specific requirements, consult the IAPMO-UES ER-192 listing and your local building code for confirmation.

What drive tool is compatible with this screw?

This screw uses a 5/16 in. hex drive, which is compatible with standard 5/16 in. hex-drive bits used with drills and impact drivers - tools commonly found on framing job sites and in DIY workshops.