Simpson #12 x 2" Self-Drilling Flat-Head Screw with Wing is a precision-engineered fastener from Simpson designed for securely attaching wood, plywood, and fiber cement to steel substrates up to 0.209" thick. The winged drill point bores a clean clearance hole through the wood layer so the material does not climb the shank during installation - then the wings snap off cleanly as the point contacts the steel, delivering a flush, professional finish. Built from Type 410 stainless steel with an added corrosion-protection coating, this self-drilling fastener is a reliable choice for demanding construction and structural applications where both strength and durability are required.

Key Features

• Type 410 stainless steel with corrosion-protection coating - can be hardened through heat treatment, giving it the ability to drill through metal while the coating adds an extra layer of protection against rust and environmental exposure
• Winged drill point (Point Size 3) - wings bore a clearance hole through wood or plywood so the workpiece does not ride up the shank, then break off cleanly when the point contacts steel, ensuring a tight, properly seated connection
• Flat countersunk head with self-countersinking nibs - seats flush with the surface automatically during installation, eliminating the need for a separate countersinking step and delivering a clean, finished appearance
• #3 square drive - provides excellent bit engagement and reduces cam-out during installation, improving torque transfer and overall installation speed
• Machine screw thread, full-length, 24 TPI - full thread engagement along the entire shank maximizes holding strength in steel, and the 24 TPI pitch is optimized for threading into metal substrates
• Shank slot - enhances thread formation in steel and channels away exhaust material, reducing heat buildup and improving drilling performance in metal
• #12 diameter, 2" length - sized appropriately for 1" and 5/4" boards, providing the correct grip length (max. 1.875") for secure fastening without overdriving

Why This Product

• Engineered specifically for wood-to-steel fastening - the winged point solves the common problem of the wood workpiece climbing the shank during drilling, a frustration with standard drill-point screws in composite assemblies
• No pre-drilling required - the self-drilling point with wings handles both the clearance hole in the wood and the pilot hole in the steel in a single driving operation, saving time on the job
• Works through steel up to 0.209" thick - the heat-treatable Type 410 stainless steel construction gives this fastener the hardness needed to penetrate light-gauge steel framing and structural members without a separate bit or pilot step
• Flush, countersunk finish every time - the flat head with self-countersinking nibs automatically recesses into the workpiece surface, producing a professional result when fastening fiber cement siding, plywood panels, or dimensional lumber to steel

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #12
• Length: 2 in.
• Head Diameter: 0.380 in.
• Head Type: Flat Head
• Drive Type: #3 Square
• Shank Type: Shank Slot
• Thread Type: Machine Threads
• Thread Length: Full
• TPI: 24
• Max. Grip Length: 1.875 in.
• Point Type: Drill Point with Wings
• Point Size: 3
• Material: Type 410 Stainless Steel
• Country of Origin: Taiwan

Available Pack Options

• F12C200FDC: 100 Pk
• F12C200FDM: 1000 Pk
• F12C200FDB: 2500 Pk

Approved Applications

• Securing wood to steel substrates up to 0.209" thick
• Attaching plywood to light-gauge steel framing
• Fastening fiber cement panels to steel structural members
• 1" and 5/4" board attachment to steel (2" length)

Frequently Asked Questions

What is the maximum steel thickness this screw can drill through?

This screw is rated for use with steel substrates up to 0.209" thick. For heavier steel gauges beyond that thickness, a different fastener or pre-drilling may be required.

What drive bit do I need to install this screw?

This screw uses a #3 square drive. The compatible replacement bit is Simpson model BIT3S-2-R2.

How do the wings on this screw work, and why are they important?

The wings are located just above the drill point. As the screw drives through wood or plywood, the wings bore a clearance hole slightly larger than the shank, preventing the wood from gripping the threads and climbing up. When the point reaches the steel substrate, the wings break off cleanly, allowing the machine threads to engage the steel and pull the workpiece down tight. This two-stage action is essential for achieving a proper, fully seated connection.

Does Type 410 stainless steel offer the same corrosion resistance as Type 316 or Type 305?

No. While Type 410 stainless steel is coated for additional corrosion protection and can be heat-treated for the hardness needed to drill through metal, it does not offer the same level of corrosion resistance as Type 316 or Type 305 stainless steel. For applications with sustained exposure to saltwater or highly corrosive environments, a higher-grade stainless fastener may be more appropriate.

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