Simpson Strong-Drive DWP Wood Screw in #12 x 3" with Type 316 Stainless Steel Flat Head is a load-rated structural fastener engineered for demanding exterior applications where corrosion resistance and verified load performance are non-negotiable. Designed specifically for decks, docks, boardwalks, and other outdoor wood connections exposed to moisture, saltwater, or chemically aggressive environments, this screw delivers the holding strength and long-term durability that exterior structural work demands. Its T27 6-lobe drive, sharp point, and unique box thread design make it a reliable choice for both professional contractors and serious DIYers tackling exterior engineered connections.

Key Features

• Type 316 Stainless Steel material - provides superior resistance to saltwater, chlorides, and harsh outdoor environments, making it the right choice for seaside docks, waterfront boardwalks, and coastal deck construction where ordinary fasteners corrode prematurely.
• Flat head profile with 0.435" head diameter - sits flush with the wood surface for a clean, snag-free finish that is ideal for deck boards and walking surfaces.
• Unique box thread design - greatly reduces driving torque during installation, which means more screws driven per battery charge and less fatigue over long work sessions.
• Specially designed sharp point - penetrates hard wood products and engineered wood with ease, eliminating the need for pre-drilling in many applications and speeding up installation.
• T27 6-lobe drive - provides a secure, positive bit engagement that resists cam-out, extends bit life, and allows confident driving even at awkward angles.
• Load-rated per ICC-ES AC233 - tested and verified for shear, pull-through, and withdrawal resistance, so you can specify and document structural performance with confidence on permitted projects.
• 3" length in #12 diameter - provides deep, reliable penetration into structural members for strong withdrawal resistance in deck and dock framing connections.

Why This Product

• Built for high-corrosion and severe-exposure environments - Type 316 stainless steel outperforms standard stainless in chloride-rich settings such as marine docks, coastal boardwalks, and waterfront decks, where exposure to salt spray and moisture accelerates corrosion in lower-grade fasteners.
• Structurally verified - not just a commodity screw - testing to ICC-ES acceptance criteria AC233 with published shear, pull-through, and withdrawal load ratings means this fastener can be specified on engineered drawings and submitted for permit inspections with documented performance data.
• Faster installation without sacrificing holding power - the combination of box threads that reduce driving torque and a sharp point that bites into hardwood and engineered wood products translates directly into faster job completion and reduced tool battery drain on large deck or dock projects.
• A single fastener for multiple exterior structural uses - whether connecting deck boards to joists, assembling dock framing near open water, or securing boardwalk planking, this screw is tested and appropriate for a broad range of exterior wood-to-wood structural connections.

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #12
• Length: 3 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: 48
• Country of Origin: Taiwan

Available Pack Options

• T12300WP1: 1 Lb (48) - includes (1) T27 6-lobe driver bit
• T12300WP5: 5 Lb (240) - includes (1) T27 6-lobe driver bit
• T12300WPB: 1500 Pk - includes (2) T27 6-lobe driver bits

Approved Applications

• Deck construction and deck board fastening in exterior environments
• Dock and pier assembly near fresh or saltwater
• Boardwalk and walkway structural connections
• General exterior structural wood connections requiring load-rated fasteners
• Applications in high or severe corrosion environments including coastal and marine settings
• Connections in wood, engineered wood, and polymer materials

Frequently Asked Questions

What makes Type 316 stainless steel the right choice for dock and marine applications?

Type 316 stainless steel contains molybdenum, which significantly increases its resistance to chlorides, salt spray, and the corrosive chemicals present in marine and waterfront environments. For docks, boardwalks, and coastal decks that face continuous moisture and salt exposure, 316 stainless provides a higher level of corrosion protection than standard 304 stainless or zinc-coated fasteners - helping the connection maintain its structural integrity over time in severe-exposure conditions.

Are these screws load-rated for structural use on permitted projects?

Yes. The Strong-Drive DWP Wood SS screws have been tested in accordance with ICC-ES acceptance criteria AC233 and carry published load ratings for shear, pull-through, and withdrawal resistance. This means they can be specified on engineered structural drawings and submitted to building departments as part of a permitted deck, dock, or boardwalk project.

What is a box thread design and why does it matter for driving performance?

The box thread is a unique thread geometry used on the Strong-Drive DWP Wood SS screw that is engineered to significantly reduce the driving torque required to seat the fastener. Lower driving torque means your drill or impact driver works less hard per screw, extending battery run time and reducing driver wear - which adds up to meaningful time and cost savings on large exterior projects involving hundreds of fasteners.

What drive bit size does this screw require?

This screw uses a T27 6-lobe (Torx-style) drive, which requires a T27 bit. The 6-lobe profile creates positive engagement between the bit and the fastener head, which resists cam-out, extends the usable life of the bit, and makes it easier to drive screws confidently - including in overhead or awkward positions common on dock and deck framing work.

Note: Product dimensions may differ from picture. Please refer to the specifications listed above for accurate dimensions.