The Simpson Strong-Tie SDWS16400Q Strong-Drive SDWS Framing Screw is a 0.160 inch x 4 inch structural wood screw sold in a 750-count pack for wood-to-wood fastening. This is a structural wood screw designed for framing, remodeling, and engineered wood connections. Model Number: SDWS16400Q. If you need a fastener that installs with a driver instead of swinging a hammer, while giving better holding power than nails in many framing applications, this is the kind of screw you buy on purpose.

What makes this screw useful on the job is how it goes in. The SawTooth Type-17 point is built for fast starts and lower driving resistance, which helps eliminate predrilling in most applications. That saves time when you are running repetitive framing connections, fastening lumber, or tying members together in remodeling work. The serrated threads also help reduce installation torque, so the screw drives more efficiently and does not fight the tool as much on the way in.

The head design matters here too. Simpson uses a low profile washer head with underhead box nibs, which increases bearing surface in structural applications and helps the head seat cleanly into the wood. In plain terms, you get more clamp area than a small bugle head or typical deck screw head, which is exactly what you want when the fastener is doing real structural work. The T25 6-lobe drive also gives positive bit engagement, reducing cam-out and helping bits last longer during high-volume fastening.

For jobsite conditions, the Quik Guard coating is a big part of the value. It is intended for indoor and outdoor applications, so this framing screw works across general construction, exterior projects, and many everyday structural wood connections without stepping up to a more specialized stainless fastener. The carbon steel body provides the strength you expect from a structural screw, while the coating adds the corrosion protection needed for broader use than a basic interior-only fastener.

This specific SDWS16400Q version is the 4 inch length option with a 0.450 inch head diameter, 0.160 inch shank diameter, 8-1/2 threads per inch, and 2-1/2 inch thread length. Those numbers matter because they tell you this screw is sized for real framing and wood member tie-ins, not light trim work. The longer body gives you reach for thicker stock and stronger embedment, while the thread geometry is set up for wood-to-wood grab rather than metal fastening.

If you are a framer, remodeler, contractor, or serious DIYer working on structural wood assemblies, this is the right kind of fastener when you want speed, strong holding power, and easier installation with an impact driver or drill/driver. It is especially useful for wood framing, engineered wood applications, and indoor or outdoor projects where a code-listed framing screw makes more sense than a common nail or a generic construction screw.

Simpson Strong-Tie SDWS16400Q Strong-Drive SDWS Framing Screw Gets the Structural Stuff Done

This is the screw you grab when a regular wood screw is not enough and you want framing-friendly installation without giving up holding power.

• Who it's for: Framers, remodelers, deck builders, and serious DIYers doing wood-to-wood structural fastening.
• Why it stands out: The SawTooth point, serrated threads, washer-style low profile head, and T25 6-lobe drive all work together to make installation faster and cleaner.
• Worth knowing: This is a 750-pack of 4 inch screws, so it makes the most sense for high-volume work or stocking the shop, not one small weekend repair.

• What is this screw designed for? It is designed for wood-to-wood fastening in framing, remodeling, and engineered wood applications.
• Do I need to predrill? Simpson states the SawTooth point eliminates the need for predrilling in most applications.
• What bit do I use? This screw uses a T25 6-lobe drive.
• Can it be used indoors and outdoors? Yes. The Quik Guard coating is intended to provide protection in indoor and outdoor applications.