Simpson 4-inch 20d Annular Ring Shank Common Nail in Type 304 Stainless Steel by Simpson Strong-Tie delivers a corrosion-resistant, high-withdrawal-resistance fastening solution built for demanding wood framing and wood-to-wood attachment projects. Crafted from Type 304 stainless steel at a robust 6 gauge, this full round head nail features a diamond point for clean, accurate driving and an annular ring shank that locks into wood fibers to resist pull-out forces far beyond what a smooth shank nail can provide. Whether you are framing structural assemblies or securing exterior wood elements where moisture and the elements are a constant concern, this common nail is engineered to hold tight for the life of the structure.

Key Features

• Annular ring shank - increases withdrawal resistance so the nail grips wood fibers and stays anchored even under cyclic loading or seasonal wood movement
• Type 304 stainless steel material and finish - provides strong corrosion resistance for outdoor, wet, and high-humidity environments where standard bright or galvanized nails may degrade over time
• 6 gauge, 0.203-inch shank diameter - delivers substantial shear and holding strength suited to heavy framing and structural wood-to-wood connections
• Full round head at 7/16-inch diameter - distributes load across a wider bearing surface, reducing the chance of the head pulling through the wood member
• Diamond point tip - concentrates driving force at the point for easier penetration and cleaner entry with less wood splitting
• 4-inch length / 20d penny size - provides the depth of embedment needed for solid structural connections in dimension lumber framing applications
• Made in the United States - manufactured domestically to meet rigorous quality and material standards for professional construction use

Why This Product

• When framing exterior or moisture-exposed wood assemblies, the Type 304 stainless steel construction means the nail resists corrosion over time, helping the fastened connection maintain its integrity without rust staining or material degradation
• The annular ring shank addresses one of the most common framing challenges - fastener back-out - by mechanically interlocking with wood fibers, making this nail a reliable choice wherever withdrawal loads are a concern
• At 4 inches and 20d, this nail provides the penetration depth required for typical structural wood framing tasks, eliminating guesswork about whether the fastener is long enough for the application
• The full round head and diamond point combination makes driving faster and more consistent by hand or with a framing hammer, reducing the risk of missed strikes and surface damage to the workpiece

Specifications

• Brand: Simpson Strong-Tie
• Length: 4 in.
• Penny Size: 20d
• Gauge: 6
• Shank Diameter: 0.203 in.
• Head Diameter: 7/16 in.
• Shank Type: Annular-Ring Shank
• Head Type: Full Round Head
• Point Type: Diamond Point
• Material: Type 304 Stainless Steel
• Finish: Type 304 Stainless Steel
• Approximate Count Per Lb: 25
• Country of Origin: United States

Available Pack Options

• S20ACN1: 1 Lb (25)
• S20ACN5: 5 Lb (125)
• S20ACNB: 25 Lb (625)

Approved Applications

• Fastening Wood-to-Wood
• Framing - Wood

Frequently Asked Questions

What is the advantage of an annular ring shank over a smooth shank on a common nail?

An annular ring shank features ridges along the shank that mechanically interlock with wood fibers as the nail is driven. This significantly increases withdrawal resistance compared to a smooth shank nail, meaning the fastener is much harder to pull back out. For structural framing and wood-to-wood connections, this added grip helps maintain joint integrity under load, vibration, and seasonal wood movement.

Why is Type 304 stainless steel recommended for exterior wood framing applications?

Type 304 stainless steel offers strong corrosion resistance, making it well suited for outdoor construction and applications where wood is exposed to moisture, humidity, or wet conditions. Unlike standard bright or zinc-coated nails that can corrode and weaken over time, a stainless steel nail maintains its structural integrity and avoids rust staining on the wood surface. For seaside or highly corrosive environments, Type 316 stainless steel may be considered for even greater corrosion protection.

What does the 20d penny size indicate about this nail?

The 20d (twenty-penny) designation is a traditional sizing classification for nails that corresponds to a 4-inch length. This size is commonly used in structural wood framing because its length provides sufficient embedment depth to create strong connections through multiple members of dimension lumber.

Is this nail driven by hand or with a nail gun?

This is a loose common nail designed to be driven with a hand framing hammer. The full round head, diamond point, and 6-gauge shank are characteristic of hand-driven common nails. Always confirm that any pneumatic nailer or framing tool you intend to use is rated for the gauge, length, and head style of this nail before attempting to use it in a power tool application.