Simpson 7d Premium Siding Nail in passivated Type 316 stainless steel is engineered for demanding exterior fastening applications where corrosion resistance is critical. Designed by Simpson Strong-Tie, this 2-1/4" annular-ring shank nail is built to perform in severely corrosive environments - including coastal and seaside locations where salt air and moisture accelerate the breakdown of standard fasteners. The passivated 316 stainless steel construction ensures long-term holding power and finish integrity when securing wood siding on homes and structures exposed to harsh outdoor conditions.

Key Features

• Passivated Type 316 stainless steel material - delivers superior corrosion resistance in severely corrosive environments, including seaside and saltwater-exposed applications, helping siding stay secure and rust-free over time
• Annular-ring shank - mechanically locks into wood fibers to dramatically increase withdrawal resistance and holding power compared to smooth-shank alternatives, reducing the risk of siding loosening over time
• Full round circle-pattern head - the textured circle head pattern reduces glare for a cleaner finished appearance and accepts surface finishes and paint, blending more naturally with installed siding
• Diamond point tip - drives straight and true into wood siding, reducing board splitting during installation and making placement more precise
• 13-gauge, 0.092" shank diameter - provides a reliable balance of shank strength and minimal material displacement, appropriate for standard wood siding profiles
• 2-1/4" length (7d penny size) - sized to penetrate siding and reach adequate depth into substrate framing for a structurally sound attachment
• Made in the United States - manufactured domestically to Simpson Strong-Tie quality standards for consistent performance on every project

Why This Product

• Purpose-built for coastal and high-corrosion environments - Type 316 stainless steel with passivation treatment is specifically formulated to withstand saltwater, chemicals, and relentless moisture exposure that would rapidly degrade standard galvanized or lower-grade stainless fasteners used in seaside siding applications
• Stronger grip than smooth-shank nails - the annular-ring shank creates a mechanical interlock with wood fibers, delivering greater withdrawal resistance so siding panels stay tight even under wind load, thermal cycling, and the natural expansion and contraction of exterior wood
• Cleaner installation with less board damage - the diamond point drives true without deflecting, reducing splits in wood siding boards, while the circle-head pattern offers a surface-ready finish that accepts paint or stain for a professional result
• Trusted Simpson Strong-Tie quality - Simpson Strong-Tie is a recognized name in structural fasteners, and this nail reflects the same engineering focus the brand brings to exterior applications where long-term durability is non-negotiable

Specifications

• Brand: Simpson Strong-Tie
• Penny Size: 7d
• Length: 2-1/4 in.
• Gauge: 13
• Shank Diameter: 0.092 in.
• Head Diameter: 5/32 in.
• Shank Type: Annular-Ring Shank
• Head Type: Full Round Head
• Head Pattern: Circle Head
• Point Type: Diamond Point
• Finish: Type 316 Stainless Steel
• Material: Type 316 Stainless Steel
• Approximate Count per Lb: 215
• Country of Origin: United States

Available Pack Options

• T7KR51: 1 Lb (215)
• T7KR55: 5 Lb (1075)
• T7KR5B: 25 Lb (5375)

Approved Applications

• Fastening Wood Siding

Frequently Asked Questions

Why is Type 316 stainless steel recommended for siding in coastal or seaside environments?

Type 316 stainless steel contains a higher molybdenum content than standard 304-grade stainless, giving it significantly improved resistance to chlorides, salt spray, and moisture-driven corrosion. When passivated - as these nails are - the surface is further treated to maximize that corrosion resistance, making them an appropriate choice for wood siding installations in severely corrosive environments including oceanfront and coastal properties.

What advantage does an annular-ring shank provide over a smooth-shank nail for siding applications?

An annular-ring shank features a series of rings along the shank that mechanically interlock with wood fibers as the nail is driven. This significantly increases withdrawal resistance - the force required to pull the nail back out - compared to a smooth-shank nail of the same dimensions. For exterior siding that experiences wind loads, seasonal wood movement, and long-term weathering, this added holding power helps keep panels secure and reduces the likelihood of fastener backing out over time.

What does the circle-pattern head on this siding nail do?

The circle head pattern on this full round head nail serves two practical purposes. First, the textured pattern helps reduce surface glare compared to a plain smooth head, which is beneficial on finished exterior surfaces. Second, the pattern provides a surface that accepts paint, stain, and other topcoats more effectively, allowing the nail head to blend in with the finished siding for a cleaner, more professional appearance.

Is the diamond point on this nail important for wood siding installation?

Yes - the diamond point geometry is designed to drive straight and true when entering wood. This helps the nail stay on its intended path rather than deflecting, and it reduces the risk of splitting siding boards during installation. This is particularly important when working with thinner or more brittle wood siding profiles where board splitting at fastener locations is a common concern.

Note: Product dimensions may differ from picture. Please see the item description above for specifications.