Description

Key Features

Fast Starts, Less Effort

The SawTooth point helps this timber screw bite quickly and reduces drive effort, so you can get into framing lumber and treated wood without predrilling in most applications.

Built to Hold

A bold thread pattern and large washer head give the screw strong pull-through resistance and holding power for structural wood-to-wood fastening.

Exterior-Ready Coating

Double-barrier coating gives the Simpson Strong-Tie SDWS221000DB Strong-Drive SDWS Timber Screws (Exterior Grade) corrosion resistance comparable to hot-dip galvanization for certain exterior and preservative-treated wood applications.

Overview

The Simpson Strong-Tie SDWS221000DB Strong-Drive SDWS Timber Screws (Exterior Grade) is a structural wood screw made for heavy-duty wood-to-wood fastening. This is a timber screw designed for structural wood-to-wood connections in exterior and treated wood applications. Model Number SDWS221000DB. In this version, you get a 10 inch long screw with a 0.220 inch shank diameter, tan double-barrier coating, washer head, SawTooth point, and a 250-piece pack quantity.

What makes this screw worth using instead of a traditional lag screw or through-bolt is the install speed. The SawTooth point is built to start fast and reduce installation torque, which means less fight from the driver and less time wasted predrilling in most jobs. If you’re building ledger connections, outdoor structures, mass timber assemblies, or other structural framing where you need serious holding power without a slower bolt-up process, this screw is aimed right at that kind of work.

The thread design matters here. Simpson calls out the bold thread geometry for superior holding power, and that is the whole point of this fastener category. You’re not just pinning trim or decking. You’re making structural connections in wood members where pull resistance and grip matter. The large washer head adds more bearing area at the surface, helping spread the load better than a smaller conventional head and improving clamp-down on the connected material.

Drive performance is another strong part of the design. The 6-lobe T40 drive gives more positive bit engagement than a basic slot or Phillips style head, which helps limit cam-out and lets you keep pressure on the screw during long drives. On a 10 inch fastener, that matters. Better engagement means less stripped heads, less bit wear, and fewer interruptions when you’re sinking long screws into dense framing members or engineered wood.

Simpson also added underhead nibs so the head can seat flush with reduced splintering. That helps when you want a cleaner finish at the surface and do not want the head hanging proud. It is a practical feature, especially in visible outdoor work like pergolas, fencing, and timber details where the head needs to pull in cleanly without chewing up the surrounding wood fibers.

For exterior use, the double-barrier coating is a big part of the value. Simpson states that it provides corrosion resistance equivalent to hot-dip galvanization, making it suitable for certain exterior and preservative-treated wood applications as described in the evaluation report. That makes this screw a much better fit for outdoor framing, fencing, landscaping, and similar jobs than an uncoated interior-only fastener.

In terms of real-world use, this exterior wood screw is suited for structural wood-to-wood and engineered wood connections, including ledgers and mass timber connections such as wall-to-wall, floor-to-floor, surface splines, and lap joints. It is meant for contractors, builders, and serious DIY users who need a faster structural fastening option and do not want to mess with slower hardware where a code-recognized screw solution makes more sense.

If you are choosing fasteners for outdoor framing or large wood assemblies, this is the kind of screw you buy when you care about drive speed, holding strength, and corrosion resistance in one package. It is not a finish screw and it is not pretending to be. It is a structural fastening solution built for big wood, long drive lengths, and jobs where a regular construction screw is out of its league.

Drives Quickly Into Structural Lumber

This screw is built for long structural drives where install time matters. The point and drive system are set up to help the screw start cleanly and keep moving without the usual lag-screw hassle.

• SawTooth point helps start fast and reduces installation torque
• Predrilling is eliminated in most applications according to Simpson

Holds Tight in Heavy Wood Connections

For pergolas, ledgers, and other heavy wood assemblies, the screw geometry does more than just pull material together. It is designed to create a strong structural connection with solid bearing at the head.

• Bold thread design provides strong holding power in wood-to-wood fastening
• Large washer head creates a broad bearing area at the surface

Made for Outdoor and Treated Wood Work

Outdoor framing and treated lumber can be rough on standard fasteners. This screw uses a coating meant for that environment, so you can use one fastener family across a wide range of exterior structural work.

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

Cleaner Seating at the Surface

The head details are doing real work here. Underhead nibs help the screw seat flush with less splintering, and the T40 6-lobe drive gives better engagement for long, high-load installs.

• Underhead nibs help drive the head flush to the surface
• T40 6-lobe drive improves engagement and helps extend bit life

Key Specifications

Application	Structural wood-to-wood fastening
Length (in.)	10 in.
Shank Diameter (in.)	0.220 in.
Head Diameter (in.)	0.760 in.
Drive Type	T40 6-Lobe
Head Type	Washer Head
Point Type	SawTooth Point
Thread Length (in.)	3 in.
Coating	Double-Barrier Coating
Color	Tan
Packaging Quantity	250
Material	Steel / Alloy Steel

Compatibility

Driver Bit

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

Materials

Designed for wood-to-wood and engineered wood fastening, including ledger and mass timber connections.

Built For

Construction Carpentry General Contracting Outdoor Framing Ledger Fastening Mass Timber Connections Pergolas and Fencing DIY / Hobbyist

Pro Tip

On long structural drives like this 10 inch screw, keep steady forward pressure with the correct T40 bit and let the SawTooth point do the starting work. If you swap in a worn bit, you give up one of the biggest advantages of this screw, which is clean engagement on deep installs.

Tool Nut’s Take

Tool Nut’s Take

Simpson Strong-Tie SDWS221000DB Strong-Drive SDWS Timber Screws (Exterior Grade) is the fast way to do heavy wood fastening right

If you are tired of lag screws that take forever to install, this is the upgrade that actually saves time without giving up structural muscle.

• Who it’s for: Builders, remodelers, deck and outdoor structure crews, and serious DIY users doing structural wood-to-wood fastening.
• Why it stands out: Fast starts, strong thread hold, a real washer head, and an exterior-ready coating make it a practical structural screw instead of just a long screw.
• Worth knowing: This is a 250-pack of 10 inch screws, so it is aimed at bigger framing and timber work, not light-duty shop jobs. Make sure you have the correct T40 drive bit on hand.

Common Questions

• What is this screw designed for? It is designed for structural wood-to-wood and engineered wood fastening, including ledgers and some mass timber connections.
• Does it usually require predrilling? Simpson states that the SawTooth point eliminates the need for predrilling in most applications.
• What bit does it use? It uses a T40 6-lobe drive, and Simpson lists replacement bit BIT40T-134-R2.
• Is it suitable for exterior use? Yes, the double-barrier coating is intended for certain exterior and preservative-treated wood applications as described by Simpson.