The Simpson T20ABNB 20d x 4" Annular Ring Shank Box Nail in Type 316 Stainless Steel is engineered for demanding construction applications where superior corrosion resistance and long-term holding power are non-negotiable. Made in the United States, this 25 lb bulk pack delivers professional-grade performance in coastal, marine, and high-moisture environments. The annular ring shank dramatically increases withdrawal resistance compared to smooth-shank fasteners, while the full round checkered head provides a clean, low-glare finish that blends naturally with wood surfaces. Whether you are building permanent wood foundations, decking, or seaside structures, the Type 316 stainless steel composition ensures exceptional resistance to salt air, moisture, and corrosive elements for the life of the structure.

Key Features

• Type 316 Stainless Steel Construction: Offers superior corrosion resistance compared to Type 304, making it the ideal choice for seaside and coastal applications where exposure to salt and moisture is constant.
• Annular Ring Shank: The ringed shank profile dramatically increases withdrawal resistance, creating a more secure and lasting attachment in wood substrates - ideal where structural integrity cannot be compromised.
• Checkered Head Pattern: The checker pattern on the full round head blends seamlessly with wood grain, reduces glare from direct sunlight, and readily accepts paints, stains, and other surface finishes for a professional appearance.
• Diamond Point Tip: Precision diamond point geometry allows for clean, consistent penetration and reduces the risk of wood splitting during installation.
• Recommended for Permanent Wood Foundations: Stainless steel nails of this type are recommended for construction of permanent wood foundations per the ANSI/AF&PA Permanent Wood Foundations Design Specifications.
• Bulk 25 Lb Pack: Packaged in a 25 lb quantity for high-volume professional projects, ensuring you have the supply needed for large-scale builds.
• Made in the United States: Manufactured domestically to consistent quality standards.

Specifications

• Model Number (MPN): T20ABNB
• Material / Coating: Type 316 Stainless Steel
• Gauge: 8
• Penny Size: 20d
• Length: 4 in.
• Head Diameter: 5/16 in.
• Shank Diameter: 0.162 in.
• Shank Type: Annular-Ring Shank
• Head Type: Full Round Head
• Head Pattern: Checkered
• Point Type: Diamond Point
• Packaging Quantity: 25 Lb
• Country of Origin: United States

Approved Applications

• Seaside and Coastal Construction: The Type 316 stainless steel formulation is specifically recommended for seaside applications where salt air and moisture accelerate corrosion in lesser materials.
• Permanent Wood Foundations: Stainless steel nails of this specification are recommended for construction of permanent wood foundations in accordance with the ANSI/AF&PA Permanent Wood Foundations Design Specifications.
• High-Moisture Environments: Suited for any application requiring superior corrosion resistance where long-term fastener integrity is critical.
• Decking and Exterior Framing: The annular ring shank and corrosion-resistant material make this nail appropriate for exterior wood assemblies subject to weathering and load stress.
• Applications Requiring Surface Finishing: The checkered head accepts paints, stains, and surface finishes, making it appropriate where aesthetics and coating adhesion matter.

What's Included

• Simpson T20ABNB 20d x 4" Annular Ring Shank Box Nails, Type 316 Stainless Steel - 25 Lb bulk pack

Frequently Asked Questions

Why is Type 316 stainless steel recommended over Type 304 for this nail?

Type 316 stainless steel offers superior corrosion resistance compared to Type 304, making it the preferred choice for coastal, marine, and seaside applications where constant exposure to salt air and moisture can rapidly degrade lesser materials. For structures built near the ocean or in high-humidity environments, Type 316 provides the long-term durability needed for the life of the structure.

What advantage does the annular ring shank provide compared to a smooth-shank nail?

The annular ring shank dramatically increases withdrawal resistance compared to smooth-shank fasteners. The ringed shank profile creates a more secure and lasting attachment in wood substrates, making these nails especially well-suited for applications where structural integrity cannot be compromised, such as permanent wood foundations, decking, and seaside structures.

What types of projects are these nails best suited for?

These nails are engineered for demanding construction applications requiring superior corrosion resistance and long-term holding power. Ideal uses include permanent wood foundations, decking, and coastal or marine structures where exposure to salt air, moisture, and corrosive elements is a consistent concern.

What does the checkered head pattern on these nails offer?

The full round checkered head blends seamlessly with wood grain, reduces glare from direct sunlight, and readily accepts paints, stains, and other surface finishes, resulting in a clean, professional appearance on finished surfaces.