The Simpson Strong-Drive DWP Wood Screw in #12 x 3-1/2", Type 316 Stainless Steel with a Flat Head is a load-rated structural fastener engineered for demanding exterior applications where corrosion resistance and proven holding strength are non-negotiable. Designed for use on decks, docks, boardwalks, and other structures exposed to moisture, salt air, and severe corrosive environments, this wood screw delivers the durability and confidence that exterior structural connections require. Its unique box-thread geometry and sharp point work together to drive cleanly through wood and engineered wood products, reducing effort while maximizing holding power.

Key Features

• Type 316 Stainless Steel material - provides superior resistance to saltwater, chemicals, and harsh outdoor environments, making it the right choice for seaside, waterfront, and high-corrosion applications
• Unique box-thread design with raised-ridge technology - greatly reduces driving torque so you can drive more screws per battery charge and reduce installer fatigue on large projects
• Specially designed sharp point - penetrates hardwood and engineered wood products with ease, minimizing pre-drilling requirements and speeding up installation
• T27 6-Lobe drive - delivers a secure, positive bit fit that minimizes cam-out, resulting in easier driving and extended bit life over the course of a project
• Flat head profile at 0.435" head diameter - sits flush with the surface for a clean, finished appearance on decking, dock planking, and exterior structural connections
• Load-rated for shear, pull-through, and withdrawal resistance - tested to ICC-ES acceptance criteria AC233, giving engineers and inspectors the verified performance data they need for code-compliant structural applications
• Compatible with wood, engineered wood, and polymer materials - offers broad versatility across decking, dock, and general exterior structural framing scenarios

Why This Product

• Verified structural performance for code-sensitive projects - because these screws are tested under ICC-ES AC233 and carry published load ratings for shear, pull-through, and withdrawal, they satisfy inspection and engineering requirements that standard exterior screws cannot meet
• Engineered specifically for severe corrosion environments - Type 316 stainless steel goes beyond standard stainless grades, offering enhanced resistance in saltwater-exposed locations such as coastal docks, piers, and oceanfront decks where lesser fasteners corrode and fail prematurely
• Drives faster with less battery drain - the box-thread design with raised-ridge technology actively reduces the torque needed to seat each fastener, which translates directly to more screws per charge and faster completion on large exterior structures
• One fastener for multiple exterior structural applications - the combination of a sharp point, box threads, flat head profile, and 316 stainless steel makes this screw equally well-suited for decking, dock construction, boardwalk framing, and general exterior structural connections near water

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #12
• Length: 3-1/2 in.
• Head Type: Flat Head
• Head Diameter: 0.435 in.
• Drive Type: T27 6-Lobe
• Thread Type: Box Threads
• Point Type: Sharp Point
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Approx. Count Per Lb: 42
• Country of Origin: Taiwan

Available Pack Options

• T12350WP1: 1 Lb (42) - includes (1) T27 6-lobe driver bit
• T12350WP5: 5 Lb (210) - includes (1) T27 6-lobe driver bit
• T12350WPB: 1000 Pk - includes (2) T27 6-lobe driver bits

Frequently Asked Questions

What makes Type 316 stainless steel a better choice than standard stainless for outdoor fasteners?

Type 316 stainless steel contains a higher molybdenum content that provides enhanced resistance to chlorides and saltwater compared to standard 304 stainless steel. This makes the DWP Wood SS screw particularly well-suited for seaside structures, coastal docks, boardwalks, and any application where exposure to high or severe corrosion is a concern - exactly the environments these fasteners are designed for.

Are these screws load-rated for structural applications?

Yes. The Strong-Drive DWP Wood SS flat-head screws are structural fasteners that have been tested in accordance with ICC-ES acceptance criteria AC233. They carry published load ratings for shear, pull-through, and withdrawal resistance, making them appropriate for exterior structural connections where load specifications are required.

What materials can these screws be used with?

The Simpson Strong-Drive DWP Wood SS screw is compatible with wood, engineered wood, and polymer materials. The sharp point and box-thread design allow it to penetrate hard wood products with ease, making it a versatile solution for deck boards, dock planking, and exterior structural framing components.

What drive bit is required for the T27 6-Lobe drive?

These screws require a T27 6-Lobe (Torx-style) driver bit. The 6-lobe drive provides a secure bit-to-fastener fit that minimizes cam-out during installation, which helps extend bit life and makes driving more consistent - particularly on larger projects where many fasteners are installed in sequence.

Note: Product dimensions may differ from picture.