The Simpson Strong-Drive SDWS Timber Screw in 0.220" x 8" with a double-barrier black coating is a high-strength structural fastener engineered as a direct, code-listed alternative to through-bolting and traditional lag screws in wood framing and timber construction. Designed for both professional contractors and do-it-yourself builders, this heavy-duty timber screw delivers reliable holding power in wood-to-wood fastening applications without the need for predrilling in most situations. Its double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization, making it a trusted choice for certain exterior and preservative-treated wood applications.

Key Features

• SawTooth Point - ensures fast starts and reduces installation torque, eliminating the need for predrilling in most wood-to-wood applications so you save time on the job site
• Bold thread design at 5 TPI with a 3" thread length - delivers superior holding power in timber connections, providing a high-strength mechanical grip that rivals through-bolted assemblies
• Washer head with 0.760" head diameter - creates a large bearing area against the wood surface, distributing load effectively and reducing the risk of pull-through under structural stress
• Underhead nibs - allow the head to drive flush to the surface with reduced splintering, producing a cleaner finish with less surface damage during installation
• T40 6-Lobe drive type - provides positive bit engagement that makes driving easier, reduces cam-out, and improves driver bit life for repeated fastening tasks
• Double-barrier coating - provides corrosion resistance equivalent to hot-dip galvanization, making this screw suitable for certain exterior and preservative-treated wood applications where long-term durability matters
• Size identification on screw head - allows quick identification in the field, reducing the chance of using the wrong fastener in a structural connection
• Code listed in IAPMO UES ER-192 and meets IRC and IBC requirements - gives contractors and inspectors confidence that the fastener is approved for most common wood framing applications without additional engineering review

Why This Product

• Replaces through-bolts and lag screws without predrilling - the SawTooth point and bold thread geometry allow this screw to be driven directly into timber in most applications, cutting installation time and labor compared to traditional bolting methods
• Built for exterior and treated-lumber environments - the double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization, making this screw a reliable option where standard fasteners would corrode prematurely in outdoor or chemically treated wood conditions
• Code compliance is already documented - IAPMO UES ER-192 listing and IRC/IBC compliance for most common wood framing applications means less time spent on job-site verification and more confidence during inspections
• Engineered for confident installation by any skill level - the T40 6-Lobe drive, washer head, and SawTooth point work together so that both professional framers and DIY builders can achieve consistent, flush-driven results in wood-to-wood connections

Specifications

• Brand: Simpson Strong-Tie
• Shank Diameter (in.): 0.220
• Length (in.): 8
• Head Diameter (in.): 0.760
• Head Type: Washer Head
• Drive Type: T40 6-Lobe
• Point Type: SawTooth Point
• Thread Length (in.): 3
• TPI: 5
• Coating: Double-Barrier Coating
• Finish: Double-Barrier Coating
• Color: Black
• Country of Origin: Taiwan

Available Pack Options

• SDWS22800DBB-R50: 50 Pk - includes one 6-lobe, T40 driver bit
• SDWS22800DBBMB: 250 Pk - includes one 6-lobe, T40 driver bit
• SDWS22800DBB: 400 Pk - includes two 6-lobe, T40 driver bits

Approved Applications

• Fastening Wood-to-Wood
• Crating

Install With

• SDWS screws install best with a low-speed 1/2-in. drill and 6-lobe, T40 driver bit (included)

Frequently Asked Questions

Does this timber screw require predrilling before installation?

In most applications, predrilling is not required. The SawTooth point is specifically designed to ensure fast starts and reduce installation torque, allowing the screw to be driven directly into wood without a pilot hole in the majority of wood-to-wood fastening situations.

Is this screw suitable for use with pressure-treated or exterior wood?

Yes. The double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization, making this timber screw suitable for certain exterior and preservative-treated wood applications. Refer to the IAPMO UES ER-192 evaluation report for specifics on approved applications.

What drive bit is needed for installation?

This screw uses a T40 6-Lobe drive. Simpson recommends using a low-speed 1/2-in. drill paired with a 6-lobe T40 driver bit for best results. The T40 driver bit is included with the screws.

What building codes does this screw comply with?

This screw is code listed in IAPMO UES ER-192 and meets IRC and IBC code requirements for most common wood framing applications, providing documented compliance that supports contractor and inspection workflows.