Simpson Fiber-Cement Screw in #8 x 2-1/4", Type 316 Stainless Steel is engineered by Simpson Strong-Tie for professionals and builders who need a reliable fastener that bonds fiber-cement siding to stressed-skin panels or secures lap siding to wood framing. Type 316 stainless steel construction delivers exceptional resistance to moisture, salt exposure, and harsh outdoor environments - making this screw a dependable choice for coastal, high-humidity, and demanding exterior applications where corrosion can compromise structural integrity.

Key Features

• Type 316 Stainless Steel material - withstands saltwater, moisture, and corrosive outdoor conditions far beyond standard zinc-plated fasteners, ensuring long-term holding power in exterior siding installations
• Ribbed wafer head with self-countersinking nibs - drives flush with the surface automatically without pre-drilling a countersink, saving time and producing a cleaner finished appearance on fiber-cement panels
• Type-17 point - cuts into material on contact for fast, accurate starts without splitting or slipping, reducing installation time and effort when driving through tough fiber-cement siding
• Full-length coarse threading - maximizes grip and pull-through resistance in wood substrates, keeping fiber-cement siding firmly anchored over time even as materials expand and contract
• #2 Square drive - provides a positive, slip-resistant bit engagement that reduces cam-out, protecting the screw head and surrounding siding surface during installation
• 0.395" head diameter - sized to distribute clamping load across fiber-cement faces, reducing the risk of surface damage or cracking in brittle panel materials

Why This Product

• Purpose-built for fiber-cement siding applications - this screw is specifically designed for binding fiber-cement siding to stressed-skin panels and lap siding to wood, matching the exact performance demands of fiber-cement installation rather than relying on a generic fastener
• Type 316 stainless steel where it matters most - exterior siding faces constant moisture exposure; the 316 stainless composition is formulated to resist chloride-rich environments, making it appropriate for coastal and wet-climate building projects where lesser grades fall short
• Self-countersinking wafer head eliminates extra prep steps - the self-countersinking nibs do the work of seating the head flush, reducing the number of operations per fastener and keeping installations moving efficiently
• Trusted Simpson Strong-Tie engineering behind every fastener - Simpson Strong-Tie designs fasteners specifically for structural and cladding applications, providing builders with a product line backed by documented design intent rather than general-purpose hardware

Specifications

• Brand: Simpson Strong-Tie
• Screw Size: #8
• Length: 2-1/4 in.
• Head Diameter: 0.395 in.
• Head Type: Ribbed Wafer Head
• Drive Type: #2 Square
• Thread Type: Coarse Threads
• Point Type: Type-17 Point
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Country of Origin: Taiwan

Available Pack Options

• T08C225WQ-RP10: 10 Pk
• T08C225WQ-RP50: 50 Pk - includes (1) #2 square-drive bit included
• T08225WQ1: 100 Pk
• T08C225WQ-RP200: 200 Pk - includes (1) #2 square-drive bit included
• T08C225WQM: 1000 Pk
• T08C225WQC: 2000 Pk

Approved Applications

• Binding fiber-cement siding to stressed-skin panels
• Fastening lap siding to wood framing
• Exterior cladding installations requiring corrosion-resistant fasteners
• Coastal and high-humidity building environments where moisture resistance is critical

Frequently Asked Questions

What makes Type 316 stainless steel the right material for fiber-cement siding screws?

Type 316 stainless steel contains a higher concentration of corrosion-resistant alloys compared to standard stainless grades, making it well-suited for exterior siding applications where the fastener is exposed to moisture, rain, and potentially salt-laden air. Using a corrosion-resistant screw in fiber-cement installations helps maintain the integrity of both the fastener and the surrounding siding material over the life of the assembly.

What is a Type-17 point and why does it matter for fiber-cement installation?

A Type-17 point features a cutting tip that bores into the material rather than simply pushing through it. This design allows for faster starts in dense materials like fiber-cement siding, reduces the torque required to drive the screw, and helps prevent surface damage caused by a slipping or spinning point at the start of the drive.

What drive bit is compatible with this screw?

This screw uses a #2 Square drive. The #2 square drive interface provides a snug fit that minimizes cam-out during driving, which is especially important when working with fiber-cement panels where surface damage from a slipping bit can be difficult to repair.

What is the function of the self-countersinking nibs on the wafer head?

The self-countersinking nibs on the ribbed wafer head are small cutting features located beneath the head that score and clear material as the screw is driven home. This allows the head to seat flush with the surface of the fiber-cement siding without requiring a separate countersinking operation beforehand, simplifying installation and producing a neater finished result.

Note: Product dimensions and/or thread length may differ from picture. Please see the item description above for specifications.