Simpson 8d Fiber-Cement Siding Nail in Type 316 Stainless Steel by Simpson Strong-Tie is an 11-gauge, 2-1/2" fastener engineered expressly for securing lap and panel siding materials made of fiber-cement composites. Its annular-ring shank, diamond point, and full round head work together to deliver a firm, corrosion-resistant hold in demanding exterior siding applications - including coastal and high-moisture environments where long-term durability is essential.

Key Features

• Type 316 Stainless Steel material - provides superior corrosion resistance compared to standard stainless grades, making these nails well suited for seaside installations, high-humidity climates, and exposure to chemicals or salt air.
• Annular-ring shank - the ringed shank profile dramatically increases withdrawal resistance, helping fiber-cement siding panels stay firmly anchored over time even under wind load and thermal movement.
• Full round head with checkered pattern - the 9/32" full round head distributes clamping force evenly across the siding face, while the checkered surface blends with faux wood grain textures, reduces glare from sunlight, and accepts paint or surface finishes.
• Diamond point tip - the sharp, four-sided point allows for easier driving and cleaner penetration through fiber-cement composite materials, reducing splitting and installer fatigue.
• 11-gauge, 2-1/2" (8d) sizing - purpose-sized for the structural demands of fiber-cement lap and panel siding, providing both the shank length and shank diameter (0.120") needed for reliable attachment.
• Made in the United States - domestic manufacturing to Simpson Strong-Tie quality standards, ensuring dimensional consistency across every nail.

Why This Product

• Designed expressly for fiber-cement composite siding - not a general-purpose nail repurposed for the job - meaning the head size, shank type, and point geometry all address the specific challenges of fastening lap and panel siding without cracking or splitting the material.
• Type 316 stainless steel construction resists the staining and corrosion that can compromise standard nails in exterior applications, helping preserve the appearance and integrity of fiber-cement siding for years without rust bleed-through.
• The annular-ring shank holds tighter than smooth-shank alternatives, reducing the risk of siding panels loosening or popping away from the substrate over time - a key concern in regions with significant wind, rain, or seasonal temperature swings.
• The checkered head pattern serves a practical cosmetic function: it minimizes visible glare on installed siding and takes paint or primer the same way the siding surface does, keeping the finished exterior looking clean and uniform.

Specifications

• Brand: Simpson Strong-Tie
• Penny Size: 8d
• Length: 2-1/2 in.
• Gauge: 11
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Shank Type: Annular-Ring Shank
• Shank Diameter: 0.120 in.
• Head Type: Full Round Head
• Head Diameter: 9/32 in.
• Head Pattern: Checkered
• Point Type: Diamond Point
• Approximate Count Per Lb: 115
• Country of Origin: United States

Available Pack Options

• T8PCS1: 1 Lb (115)
• T8PCS5: 5 Lb (575)
• T8PCSB: 25 Lb (2875)

Approved Applications

• Fastening Fiber-Cement Siding

Frequently Asked Questions

Why is Type 316 stainless steel recommended for fiber-cement siding nails?

Type 316 stainless steel offers enhanced resistance to corrosion from salt air, moisture, and chemicals compared to lower-grade alloys. This makes it the appropriate choice for exterior siding fasteners - especially in coastal or high-humidity environments - because it helps prevent rust staining on the siding surface and maintains fastener integrity over the long term.

What is the advantage of an annular-ring shank over a smooth shank for siding applications?

The annular-ring shank features a series of rings along its length that grip the substrate material on all sides. This dramatically increases withdrawal resistance compared to a smooth-shank nail, so fiber-cement siding panels remain firmly attached even under the stress of wind pressure, seasonal expansion and contraction, and long-term weather exposure.

What does the checkered head pattern on these nails do?

The checkered pattern serves two practical purposes: it reduces glare from sunlight on the exposed nail head after installation, and its textured surface accepts paint and surface finishes - helping the nail head blend with the surrounding fiber-cement siding material for a cleaner finished appearance.

Are these nails compatible with both lap siding and panel siding made of fiber-cement composites?

Yes. These nails are designed expressly for use with various lap and panel siding materials made of fiber-cement composites. The 2-1/2" length, 0.120" shank diameter, diamond point, and annular-ring shank are all selected to work with the structural requirements of fiber-cement siding in both lap and panel configurations.