The Simpson Strong-Bolt 2 5/8 in. x 4-1/2 in. Wedge Anchor in Type 304 Stainless Steel is a wedge-type expansion anchor engineered for high-performance concrete fastening in the most demanding structural environments. Featuring dual undercutting embossments on each clip segment, this anchor achieves secondary expansion should a crack form and intersect the anchor location - significantly increasing load-carrying capacity even when the hole expands. From seismic and high-wind construction to everyday concrete anchoring, this stainless steel expansion anchor delivers the code-listed reliability and corrosion resistance that structural and commercial applications require.

Key Features

• Code listed for cracked and uncracked concrete applications - gives contractors and engineers confidence the anchor meets code requirements across a broader range of concrete conditions, reducing the need for separate products on the same job site.
• Dual undercutting embossments on each clip segment enable secondary expansion - if a crack intersects the anchor location, the anchor continues to carry load rather than losing holding strength, making it a reliable choice for long-term structural integrity.
• Qualified for static and seismic loading conditions (seismic design categories A through F) - covers the full range of seismic design categories, so the anchor is appropriate for virtually any geographic region or building classification without substitution.
• Suitable for horizontal, vertical, and overhead applications - provides installation flexibility for a wide variety of structural fastening tasks without requiring a different anchor style for different orientations.
• Chamfered top designed to prevent mushrooming during installation - protects the threads during driving so the nut seats cleanly, reducing installation errors and saving time on the job.
• Made from Type 304 Stainless Steel (anchor body, nut, and washer) - delivers long-lasting corrosion resistance for a wide variety of service environments, including those with elevated moisture or chemical exposure.
• Standard ANSI fractional sizing at 5/8 in. diameter - fits standard fixtures and installs with a common 5/8 in. drill bit and 15/16 in. wrench, so no specialty tooling is required.
• Tested per ACI355.2 and AC193 - independently verified to established industry testing standards, giving engineers and inspectors the documentation they need for structural approvals.

Why This Product

• Built for seismic and high-wind environments - qualified for seismic design categories A through F under both static and seismic loading conditions, this wedge anchor is a dependable solution for projects in regions where structural anchoring requirements are strictest.
• Crack-adaptive design protects long-term load capacity - the dual undercutting embossments on each clip segment allow the anchor to expand a second time if a concrete crack develops at the anchor point, a critical advantage in post-installed concrete anchoring where crack propagation is a real-world concern.
• Stainless steel construction stands up to corrosive service environments - with the anchor body, nut, and washer all manufactured from Type 304 Stainless Steel, this wedge anchor is well suited for exterior, coastal, or other corrosion-prone applications where standard carbon steel anchors would degrade prematurely.
• Installs with common tools and standard fixtures - the ANSI fractional 5/8 in. size works with everyday drill bits and wrench sizes, eliminating the learning curve and extra tooling costs that can come with specialty fastener systems.

Specifications

• Model No.: STB2-62412S4F20
• Coating/Material: Type 304 Stainless Steel
• Size (in.): 5/8 in. x 4-1/2 in.
• Drill Bit Diameter (in.): 5/8 in.
• Thread Length (in.): 2-7/16 in.
• Component Material, Anchor Body: Type 304 Stainless Steel
• Component Material, Nut: Type 304 Stainless Steel
• Component Material, Washer: Type 304 Stainless Steel
• Component Material, Clip: Type 304 or Type 316 Stainless Steel
• Packaging: Packs of 20 and Cartons of 80

Frequently Asked Questions

Is the Strong-Bolt 2 suitable for use in cracked concrete?

Yes. The Strong-Bolt 2 is code listed for both cracked and uncracked concrete applications. Its dual undercutting embossments on each clip segment enable secondary expansion should a crack form and intersect the anchor location, significantly increasing the anchor's ability to carry load if the hole expands.

What material is this anchor made from?

The anchor body, nut, and washer are all manufactured from Type 304 Stainless Steel. The clip component is made from either Type 304 or Type 316 Stainless Steel, providing long-lasting corrosion resistance for a wide variety of service environments.

What drill bit size is required for installation?

A 5/8-inch diameter drill bit is required to install the STB2-62412S4F20 wedge anchor.

Can this anchor be used in seismic or high-wind applications?

Yes. The Strong-Bolt 2 wedge-type expansion anchor is an optimal choice for high-performance applications, including those subject to seismic and high-wind conditions.

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