Description

Key Features

Fast Starts

The SawTooth point starts quickly and usually skips the need for predrilling in wood. That means less setup and less strain on your drill when you are driving structural screws all day.

Structural Hold

The bold thread design gives the Simpson Strong-Tie SDWS22400DBMB Strong-Drive SDWS Timber Screws (Exterior Grade) the holding power needed for demanding wood-to-wood connections like ledgers, posts, and heavy framing details.

Built for Exterior Use

Double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization for certain exterior and preservative-treated wood applications. That matters when the fastener is going into outdoor builds that need to stay tight over time.

Overview

The Simpson Strong-Tie SDWS22400DBMB Strong-Drive SDWS Timber Screws (Exterior Grade) is a 4 inch structural wood screw for exterior wood-to-wood fastening. This is a structural wood screw designed for fastening wood members in outdoor and treated-lumber applications. Model Number: SDWS22400DBMB. With its 0.220 inch shank, washer head, and aggressive thread, this screw is built for contractors and serious DIY users who want a faster alternative to traditional lag screws or through-bolting in many structural wood connections.

What makes this screw matter on the job is how it cuts down installation time without giving up holding power. Simpson Strong-Tie uses a bold thread design for strong grip in wood, and the SawTooth point is there for one simple reason: faster starts with less effort. In most applications, that means no predrilling, which saves time on repetitive fastening and helps when you are working overhead, on ladders, or moving through a ledger or railing job where every extra step slows you down.

The head and drive design are just as important as the thread. This screw uses a T40 6-lobe drive for more positive bit engagement, so the bit stays seated better under load and is less likely to cam out when you are driving into dense framing or engineered wood. The washer head spreads clamping force over a larger area than a standard screw head, which helps pull members tight and hold them there. Underhead nibs help the head sit flush with less splintering at the surface, so the finished connection looks cleaner and seats more consistently.

For this specific version, Simpson Strong-Tie pairs the 4 inch length with a 2-3/8 inch thread length and a 0.760 inch head diameter. That combination gives you a screw that is long enough for many common structural wood connections while still being manageable to drive with a standard drill or impact driver using the correct T40 bit. The head is also marked for size identification, which is a small detail but a useful one when you have different lengths open on the same jobsite.

This screw is also meant for exterior conditions where corrosion resistance matters. The double-barrier coating is rated by Simpson Strong-Tie as providing corrosion resistance equivalent to hot-dip galvanization, making it suitable for certain exterior and preservative-treated wood applications as described in the evaluation report. If you are building outdoors, tying ledgers, assembling fencing, or working on pergolas, planter boxes, and similar exposed structures, that coating is not a throwaway spec. It is a big part of why this fastener belongs in those jobs.

Application-wise, Simpson Strong-Tie positions the SDWS timber screw for structural wood-to-wood and engineered wood fastening, including ledgers and mass timber connections such as cross-laminated timber wall-to-wall, floor-to-floor, surface splines, and lap joints. That gives this fastener a broader use range than a basic exterior wood screw. It is not just for decking or trim. It is intended for structural fastening where holding strength and repeatable installation matter.

If you are the buyer comparing this to a lag screw, here is the practical difference: this style of structural screw is usually quicker to install, easier to drive, and simpler to use in repetitive work. You still need to follow approved application guidance, but for the right wood-to-wood connection, it is a cleaner and faster way to get the job done. For fence rails, ledger details, heavy outdoor assemblies, and general exterior structural wood fastening, this 250-count pack makes sense for crews who want jobsite-ready quantity without stepping up to a bulk contractor bucket.

Drive Structural Screws Faster

This screw is built to speed up exterior wood fastening without turning the job into a pilot-hole routine. On rails, posts, and similar assemblies, the point geometry helps the screw bite quickly so you can keep moving.

• SawTooth point is designed for fast starts
• Predrilling is eliminated in most applications

Hold Members Tight

The large washer head is there to do real work, not just look different. It gives the screw more bearing area so it can pull wood members together firmly in structural wood-to-wood connections.

• Washer head increases bearing surface
• Bold thread design provides superior holding power

Made for Outdoor Wood Projects

Outdoor structural fastening needs a screw that can handle treated lumber and exposed conditions. The double-barrier coating is a major reason this screw fits pergolas, fences, ledgers, and similar exterior work.

• Double-barrier coating provides corrosion resistance equivalent to hot-dip galvanization
• Suitable for certain exterior and preservative-treated wood applications

Clean Seating, Less Fight

Some structural screws drive hard and chew up bits. This one uses a T40 6-lobe drive for solid engagement, and the underhead nibs help the head finish flush with less surface tear-out.

• T40 6-lobe drive improves bit engagement and bit life
• Underhead nibs help reduce splintering as the head seats flush

Key Specifications

Application	Fastening wood-to-wood
Length	4 in.
Shank Diameter	0.220 in.
Head Diameter	0.760 in.
Thread Length	2-3/8 in.
Drive Type	T40 6-lobe
Head Type	Washer head
Point Type	SawTooth point
Coating	Double-barrier coating
Color	Tan
Packaging Quantity	250
Material	Steel

Compatibility

Drive Interface

Uses a T40 6-lobe drive. Simpson Strong-Tie lists replacement driver bit BIT40T-134-R2.

Material Use

Designed for structural wood-to-wood and engineered wood fastening, including ledgers and certain mass timber connections.

Outdoor Applications

Double-barrier coating is intended for certain exterior and preservative-treated wood applications as described in the evaluation report.

Built For

Construction General Contracting Carpentry Remodeling Outdoor Framing Ledger Fastening Fence and Pergola Builds DIY / Hobbyist

Pro Tip

When you are running a lot of these in treated lumber, use the correct T40 bit and keep steady pressure on the drill as the washer head seats. That gets you full engagement and helps avoid chewing up the drive on repetitive installs.

Tool Nut’s Take

Tool Nut’s Take

One of the easier ways to get structural wood connections done without messing with lag screws

The Simpson Strong-Tie SDWS22400DBMB Strong-Drive SDWS Timber Screws (Exterior Grade) gives you the kind of speed, bite, and exterior-ready protection that makes sense for real wood framing and outdoor build work.

• Who it’s for: Contractors, remodelers, deck and fence builders, and serious DIY users working on structural wood-to-wood fastening outdoors.
• Why it stands out: The fast-start SawTooth point, strong thread design, washer head, and T40 drive make it quicker and cleaner to run than a lot of old-school alternatives.
• Worth knowing: This is a 250-count tan pack, so it is a good fit when you need jobsite quantity. Just make sure you are matching it to approved structural applications and using the right T40 bit.

Common Questions

• What kind of fastening is this screw designed for? It is designed for structural wood-to-wood fastening, including ledgers and certain engineered wood and mass timber connections.
• Does this screw usually require predrilling? Simpson Strong-Tie states the SawTooth point eliminates the need for predrilling in most applications.
• What driver size does it use? This screw uses a T40 6-lobe drive.
• Is this version intended for exterior use? Yes. It has a double-barrier coating that Simpson Strong-Tie says provides corrosion resistance equivalent to hot-dip galvanization for certain exterior and preservative-treated wood applications.