Description:

Key Features

Built for Harsh Exteriors Type 316 stainless steel gives this screw the corrosion resistance you want for docks, boardwalks, and other wet or coastal jobs where ordinary exterior fasteners are not enough. Drives Easier in Wood The box thread design with raised-ridge technology is made to cut driving torque, so you can run fasteners into wood, engineered wood, and polymer boards with less strain on the drill and battery. Secure T27 Drive This Simpson Strong-Tie wood screw uses a T27 6-lobe drive for better bit engagement, easier driving, and less chance of stripping the head when you are setting long fasteners flush.

Overview

The Simpson Strong-Tie T12400WP5 Strong-Drive DWP WOOD SS Screw is a #12 x 4 in. exterior wood screw built for wood-to-wood fastening in tough outdoor conditions. This is a wood screw designed for fastening decking, dock components, boardwalk parts, and general exterior wood assemblies. Model Number T12400WP5. If you need long stainless fasteners that hold up where moisture and corrosion are real concerns, this is the kind of screw you reach for.

What matters here is not just that it is stainless, but that it is Type 316 stainless steel. That makes it a strong fit for seaside and other high-corrosion environments where standard coated screws or lower-grade stainless options can come up short over time. For dock work, waterfront structures, and exposed exterior carpentry, that extra corrosion resistance is the whole point.

Simpson designed the Strong-Drive DWP WOOD SS Screw with a sharp point and its box thread pattern to make long screws easier to drive into wood, engineered wood, and polymer materials. In real use, that means the screw starts faster and takes less effort to run home, especially when you are driving repeated fasteners into decking or structural trim. Lower driving torque also helps you get more work done per battery charge when you are using a cordless drill or impact driver with the proper bit.

The head and drive setup are also jobsite-friendly. This fastener uses a flat head so it seats cleanly when you need a flush finish, and the T27 6-lobe drive gives the bit a more secure fit than a basic recess. That translates into better control, less wobble under load, and less damage to the drive recess when you are installing long screws in dense material.

At 4 inches long with a #12 screw size, this version is aimed at heavier exterior fastening tasks where you need deeper pull and more bite than a shorter deck screw can offer. The published thread length for the T12400WP family is 2.83 inches, which helps explain why it is suited to thicker member connections in deck and exterior framing applications. Simpson also lists this size for deck, dock, and boardwalk use, which is exactly where a long stainless flat head screw earns its keep.

This specific T12400WP5 version is the 5 lb package, making it a practical buy for larger outdoor builds or contractors who do not want to run short midway through a job. Based on the manufacturer table, the pack is approximately 36 screws per pound, so this package is intended for real project volume rather than a couple of repair screws in a drawer.

If you are building or repairing exterior wood structures, especially around water or salt exposure, this screw makes sense. It is a good fit for deck builders, marine contractors, remodelers, and serious DIY users who want one fastener that drives cleanly and lasts. If your job is inland and lightly exposed, Type 316 may be more screw than you need. But if corrosion is the problem, this is the right kind of answer.

Made for Wet and Coastal Jobs

This screw is built for the kind of exterior work that beats up ordinary fasteners. Type 316 stainless steel is the big reason to buy it if you are working around water, treated lumber, or salt-heavy air.

• Type 316 stainless steel for higher corrosion resistance
• Listed for decking, docks, boardwalks, and general exterior applications

Drives with Less Fuss in Dense Material

The thread design is not just there for looks. Simpson's box thread pattern is intended to reduce driving torque, which helps the screw pull into the material with less resistance and less battery drain.

• Box threads with raised-ridge technology reduce driving torque
• Sharp point penetrates wood, engineered wood, and polymer materials more easily

Better Bit Fit, Cleaner Flush Finish

Long exterior screws are easier to live with when the bit stays engaged and the head seats cleanly. The T27 6-lobe recess helps keep control on the drill, while the flat head is made for flush wood-to-wood fastening.

• T27 6-lobe drive for secure bit engagement and longer bit life
• Flat head design for a flush finished surface

Key Specifications

Compatibility

Bit Interface Uses a T27 6-lobe drive bit. Work Materials Designed for use with wood, engineered wood, and polymer materials.

Built For

Deck Building Docks Boardwalks Exterior Carpentry Marine Environments Remodeling

Pro Tip

Use a fresh T27 6-lobe bit when you are driving these long screws into dense exterior stock. You will get better engagement, less head wear, and an easier time setting the flat head flush without chewing up the recess.

Tool Nut's Take

Tool Nut's Take

Simpson Strong-Tie T12400WP5 Strong-Drive DWP WOOD SS Screw is the one you buy when corrosion is the real jobsite problem

This is a purpose-built exterior fastener for guys who would rather do the job once than come back later and replace rusted hardware.

• Who it's for: Deck builders, dock crews, remodelers, and serious DIY users working on exposed outdoor wood structures.
• Why it stands out: Type 316 stainless steel, a sharp point, and a lower-torque box thread design make it a better fit for wet and coastal work than generic exterior wood screws.
• Worth knowing: This is a 5 lb package and it uses a T27 6-lobe bit. If you do not need marine-grade corrosion resistance, there are cheaper fasteners out there, but they are not built for the same abuse.

Common Questions

• What is this screw made for? It is made for fastening wood to wood in decking, docks, boardwalks, and other exterior applications.
• What bit does it use? This screw uses a T27 6-lobe drive.
• What materials can it be used with? Simpson lists it for wood, engineered wood, and polymer materials.
• Why choose the Type 316 version? Type 316 stainless steel is recommended where extra corrosion protection matters, especially in seaside or harsh outdoor environments.