The Simpson Strong-Bolt 2 Wedge Anchor (1/2 in. x 3-3/4 in., Zinc-Plated Carbon Steel) is a wedge-type expansion anchor engineered for high-performance structural connections in demanding seismic and high-wind conditions. Built by Simpson, this anchor is code listed for use in both cracked and uncracked concrete as well as masonry, and qualifies for static and seismic loading across seismic design categories A through F. 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 - making it a reliable solution for contractors and engineers who need dependable holding strength where it matters most.

Key Features

• Code listed for cracked and uncracked concrete, and masonry applications - gives contractors and engineers the documentation and confidence needed to specify this anchor across a wide range of structural concrete and masonry projects.
• Qualified for static and seismic loading conditions (seismic design categories A through F) - suitable for use in virtually any seismic zone in the U.S., reducing the need to source different anchors for different job sites.
• Dual undercutting embossments on each clip segment enable secondary expansion - should a crack form and intersect the anchor location, the anchor re-engages to maintain load-carrying capability, a critical safety advantage in seismic environments.
• Chamfered top designed to prevent mushrooming during installation - protects the anchor during driving, helping ensure a clean, consistent installation and reducing the risk of damaged hardware.
• Suitable for horizontal, vertical, and overhead applications - provides installation flexibility across a variety of orientations without requiring different anchor types for each.
• Tested per ACI355.2 and AC193 - independently verified performance gives engineers the third-party testing data required for code-compliant structural design.
• Made from zinc-plated carbon steel - provides a corrosion-resistant finish appropriate for standard interior and protected structural applications.
• Installs with a 1/2 in. drill bit and 3/4 in. wrench - straightforward tooling requirements keep installation fast and efficient with common jobsite equipment.

Why This Product

• Built for seismic and high-wind structural work - the Strong-Bolt 2 is specifically engineered and code listed for seismic design categories A through F, making it one of the few wedge anchors fully qualified for the most demanding wind and seismic connection requirements.
• Performs even when concrete cracks - the dual undercutting embossment design enables secondary expansion if a crack intersects the anchor location, maintaining load capacity under conditions that would compromise a standard wedge anchor.
• Versatile enough to cover most concrete and masonry anchoring needs - code-listed performance in cracked concrete, uncracked concrete, and masonry, combined with approval for horizontal, vertical, and overhead installations, means this anchor adapts to a broad range of structural and construction applications.
• Independently tested for code-compliant specification - testing per ACI355.2 and AC193 provides the verified load data that engineers and inspectors require, helping projects move forward without anchor-related submittal delays.

Specifications

• Model Number: STB2-50334F25
• Size: 1/2 in. x 3-3/4 in.
• Diameter: 1/2 in.
• Length: 3-3/4 in.
• Thread Length: 2-1/16 in.
• Material: Carbon Steel
• Coating/Finish: Zinc Plated
• Required Drill Bit Diameter: 1/2 in.
• Required Wrench Size: 3/4 in.
• Packaging: Packs of 25 and Cartons of 125

Approved Applications

• Cracked concrete
• Uncracked concrete
• Masonry
• Horizontal installations
• Vertical installations
• Overhead installations
• Seismic and high-wind structural connections (seismic design categories A through F)
• Static loading conditions

Frequently Asked Questions

What makes the Strong-Bolt 2 suitable for seismic applications?

The Strong-Bolt 2 is qualified for static and seismic loading conditions across seismic design categories A through F. Its dual undercutting embossments on each clip segment enable secondary expansion should a crack form and intersect the anchor location, which significantly increases the anchor's ability to carry load even if the hole expands - a critical performance advantage in seismic and high-wind environments.

Can this anchor be used in cracked concrete?

Yes. The Strong-Bolt 2 is code listed for use in both cracked and uncracked concrete, as well as masonry applications. It has been tested per ACI355.2 and AC193 to confirm performance in these conditions.

What tools are needed to install this wedge anchor?

Installation requires a 1/2 in. drill bit to prepare the hole and a 3/4 in. wrench to tighten the anchor. The chamfered top is specifically designed to prevent mushrooming of the bolt head during the installation process.

Is this anchor approved for overhead and horizontal installations?

Yes. The Strong-Bolt 2 is suitable for horizontal, vertical, and overhead applications, providing flexibility across a wide range of structural fastening scenarios.

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