Key Features

Fast Starts The SawTooth point bites quickly and cuts installation torque, so this timber screw goes in faster and usually without predrilling in wood-to-wood connections. Strong Hold A bold thread design and large washer head give the screw solid pull-through resistance and holding power for structural wood fastening. Built for Exterior The double-barrier coating is made for certain exterior and preservative-treated wood applications, giving this Simpson Strong-Tie SDWS22400DB timber screw the corrosion resistance it needs outdoors.

Overview

The Simpson Strong-Tie SDWS22400DB Strong-Drive SDWS Timber Screw is a 4 inch exterior-grade structural wood screw built for wood-to-wood fastening in framing, ledger, and timber connections. This is a timber screw designed for structural wood-to-wood fastening. Model Number: SDWS22400DB. If you want a faster alternative to through-bolting or traditional lag screws, this is the kind of fastener that cuts steps out of the job without giving up the holding power you need.

For this specific version, you are getting a tan, double-barrier coated screw with a 0.220 inch shank diameter, 4 inch overall length, 2-3/8 inch thread length, 0.760 inch washer head, and a T40 6-lobe drive. Those numbers matter because they tell you what kind of bite, bearing area, and drive engagement you can expect. The large washer head spreads load over a wider area than a typical bugle or flat head wood screw, which is exactly what you want when you are pulling structural members together.

Where this screw earns its keep is installation speed. Simpson Strong-Tie uses a SawTooth point that helps the screw start quickly, reduces the torque needed to drive it, and eliminates predrilling in most applications. On the job, that means fewer wasted motions and less fighting the fastener, especially when you are running repeated connections in treated lumber, ledgers, fencing, pergolas, or heavy outdoor assemblies.

The drive system is just as important. The T40 6-lobe drive gives better bit engagement than a slotted or Phillips-style head in this kind of heavy fastening. That reduces cam-out, helps preserve the recess, and makes it easier to keep steady pressure on the screw while pulling thick stock together. Simpson Strong-Tie also marks size identification on the screw heads, which sounds like a small detail until you are sorting mixed hardware on site and need to confirm what you are driving.

Design-wise, this screw is built around practical jobsite performance. The bold thread pattern is there for holding power, while the underhead nibs help the washer head seat flush with less splintering at the wood surface. That matters when you are fastening visible exterior members and want a cleaner finished look without constantly backing screws out to correct mushrooming or torn grain around the head.

For exterior work, the double-barrier coating is a major part of the story. Simpson Strong-Tie rates it with corrosion resistance equivalent to hot-dip galvanization for certain applications, which makes it suitable for select exterior and preservative-treated wood uses as described in the evaluation report. In plain terms, this is not just a general interior wood screw painted tan. It is meant for serious outdoor structural fastening where exposure and treated lumber are part of the equation.

The SDWS line is also broad enough that the platform makes sense if you use multiple lengths across similar jobs. The family covers a wide range of lengths, but this SDWS22400DB hits a useful middle ground for many 4 inch fastening tasks. It is commonly used in structural wood-to-wood and engineered wood connections, including ledgers and mass timber applications such as CLT wall-to-wall, floor-to-floor, surface splines, and lap joints when specified.

Who should buy it? Contractors, remodelers, deck and pergola builders, fence installers, and serious DIYers working on exterior wood projects. If you are doing light trim work, this is the wrong fastener. If you are joining substantial wood members and want faster installation than lag screws with less hassle than bolts, the Simpson Strong-Tie SDWS22400DB Strong-Drive SDWS Timber Screw is exactly the right kind of hardware.

Drives Quickly Into Structural Wood

This screw is built to save time when you are making repeated structural connections. The point starts fast, the drive holds the bit well, and the threads pull material together without the usual lag-screw drama.

• SawTooth point helps eliminate predrilling in most wood applications
• T40 6-lobe drive improves engagement and helps reduce cam-out

Made for Exterior Connections

Outdoor wood projects demand more than just length and thread. The coating on this screw is what makes it a real option for certain exterior and preservative-treated wood jobs where corrosion resistance matters.

• Double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization
• Suitable for certain exterior and treated wood applications as described by Simpson Strong-Tie

Pulls Members Together Cleanly

The head design does real work here. A wide washer head gives the screw more bearing area, while the nibs under the head help it seat down flush with less surface tear-out.

• 0.760 inch washer head spreads load across the wood surface
• Underhead nibs help reduce splintering as the head seats flush

Useful Across Outdoor Wood Builds

Not every structural screw is practical for varied site work. This one works well anywhere you need a strong exterior wood screw that installs fast and leaves a clean, flush result.

• Used for wood-to-wood fastening, ledgers, and other structural exterior assemblies
• Good fit for contractors and serious DIY users building with heavy wood members

What’s in the Box

• (600) Simpson Strong-Tie SDWS22400DB timber screws
• (1) T40 6-lobe driver bit

Key Specifications

Compatibility

Bit Interface Uses a T40 6-lobe drive. Replacement Bit Replacement driver bit: BIT40T-134-R2. Material Fit Designed for wood-to-wood and engineered wood structural fastening applications.

Built For

Construction General Contracting Deck and Ledger Fastening Pergolas Fencing Mass Timber Connections Remodeling DIY / Hobbyist

Pro Tip

Let the SawTooth point start cutting before you really lean on the driver. With these screws, steady pressure and a clean T40 bit usually gets you a straighter, flush seat and saves the drive recess from unnecessary wear.

Tool Nut’s Take

Tool Nut’s Take

Why the Simpson Strong-Tie SDWS22400DB Strong-Drive SDWS Timber Screw earns a spot in the trailer

This is the kind of structural wood screw that makes outdoor timber work faster, cleaner, and a lot less annoying than driving old-school lag screws.

• Who it’s for: Builders, remodelers, deck crews, fence installers, and serious DIYers doing real wood-to-wood structural fastening.
• Why it stands out: Fast-start SawTooth point, strong thread grip, wide washer head, and exterior-ready coating are all working toward the same goal: easier installs with dependable holding power.
• Worth knowing: This is a purpose-built structural fastener, not a general wood screw. If your job does not need a heavy 0.220 inch shank and washer head, you are probably overbuying.

Common Questions

• What is this screw designed for? It is designed for structural wood-to-wood fastening, including applications such as ledgers and certain mass timber connections.
• Does it usually require predrilling? No. Simpson Strong-Tie states the SawTooth point eliminates the need for predrilling in most applications.
• What drive size does it use? It uses a T40 6-lobe drive.
• Is this an exterior fastener? Yes. The SDWS22400DB uses a double-barrier coating intended for certain exterior and preservative-treated wood applications.