Simpson Deck-Drive DWP Wood Screw in #12 x 4" Type 316 Stainless Steel is a heavy-duty fastener engineered for deck, dock, boardwalk, and general exterior wood applications where superior corrosion resistance is essential. Featuring a specially designed sharp point and unique box-thread profile, this flat-head wood screw drives smoothly into hardwood, engineered wood, and polymer decking materials - making it a reliable choice for coastal, seaside, and high-moisture environments where standard fasteners fall short. The T27 6-lobe drive system ensures a secure bit engagement, reducing cam-out and extending bit life on demanding projects.

Key Features

• Type 316 Stainless Steel material - provides exceptional resistance to saltwater, moisture, and harsh outdoor conditions, making it ideal for coastal and seaside decking projects where corrosion is a primary concern.
• Unique box-thread design with raised-ridge technology - greatly reduces driving torque, allowing you to drive more screws on a single battery charge and reducing installer fatigue on large deck projects.
• Specially designed sharp point - penetrates hardwood, engineered wood, and polymer decking materials with ease, eliminating the need for pre-drilling in most applications and speeding up installation.
• T27 6-lobe drive system - delivers a secure, precise bit fit that minimizes slipping and cam-out, resulting in cleaner drives, less surface damage, and longer bit life over the course of a job.
• Flat head profile with 0.440 in. head diameter - sits flush with or just below the deck surface for a clean, professional finish that won't snag or create trip hazards.
• 7 TPI box threads - optimized for the majority of today's deck board woods, providing strong holding power while reducing splitting risk in wood and composite materials.
• T27 6-lobe bit included (BIT27T-2) - means you can get started immediately without searching for a compatible bit, saving time on the job site.

Why This Product

• Built for coastal and high-moisture environments - Type 316 stainless steel offers a higher grade of corrosion resistance than standard stainless steel, making this screw the appropriate fastener choice for seaside decks, docks, and boardwalks exposed to salt air and standing water.
• Drives faster and easier than conventional screws - the combination of sharp point penetration and box-thread raised-ridge technology reduces driving torque so crews can complete more fastening per battery charge, improving productivity on large decking installations.
• Versatile fit for today's decking materials - designed to work with wood, engineered wood, and polymer materials, this screw handles the wide variety of modern deck board products without requiring multiple fastener types on a single project.
• Complete drive system in one - the included T27 6-lobe driver bit pairs precisely with the screw head geometry, ensuring consistent, stripped-free installation from the first fastener to the last.

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #12
• Length: 4 in.
• Head Type: Flat Head
• Head Diameter: 0.440 in.
• Drive Type: T27 6-Lobe
• Thread Type: Box Threads
• TPI: 7
• Point Type: Sharp Point
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Color: None
• Approx. Count per Lb.: 36
• Country of Origin: Taiwan

Available Pack Options

• T12400WP-RP5: 5 Pk - includes (1) T27 6-lobe bit included (BIT27T-2)
• T12400WP-RP20: 20 Pk - includes (1) T27 6-lobe bit included (BIT27T-2)

Approved Applications

• Decking, docks, and boardwalks
• Finishing, millwork, and trim
• General exterior wood applications requiring extra corrosion protection
• Seaside and coastal installations
• Wood, engineered wood, and polymer decking materials

Frequently Asked Questions

What makes Type 316 stainless steel different from other finishes for outdoor screws?

Type 316 stainless steel contains a higher molybdenum content than standard 304 stainless, which gives it enhanced resistance to saltwater, chlorides, and harsh chemical environments. This makes it the preferred material for decks, docks, and boardwalks in coastal and seaside locations where standard fasteners would corrode prematurely.

Do I need to pre-drill before driving these screws into hardwood deck boards?

In most cases, no. The specially designed sharp point on the DWP Wood screw is engineered to penetrate hardwood, engineered wood, and polymer deck board materials without pre-drilling, making installation faster and more straightforward on typical decking projects.

What driver bit do I need for the T27 6-lobe drive?

These screws require a T27 6-lobe bit. A T27 6-lobe bit (BIT27T-2) is included with your purchase, so you can begin driving immediately without sourcing a separate bit. The 6-lobe geometry provides a secure fit that minimizes cam-out and extends bit life compared to standard drive types.

Can these screws be used for fascia and trim in addition to decking?

Yes. According to Simpson, the DWP Wood SS screw is offered in a variety of sizes to fasten fascia and trim in addition to its primary deck and dock applications. It is also suitable for finishing and millwork where corrosion-resistant exterior fasteners are needed.

Note: Product dimensions and/or thread length may differ from picture.