The Simpson Strong-Bolt 2 1/2 in. x 4-3/4 in. Wedge Anchor is a wedge-type expansion anchor engineered by Simpson for high-performance structural connections in cracked and uncracked concrete, as well as masonry. 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 choice for seismic and high-wind conditions. Manufactured from zinc-plated carbon steel, this anchor is tested per ACI355.2 and AC193 and is suitable for horizontal, vertical, and overhead installations across the full range of seismic design categories.

Key Features

• Dual undercutting embossments on each clip segment - enable secondary expansion if a crack intersects the anchor location, helping maintain load capacity when concrete conditions change
• Code listed for cracked and uncracked concrete, and masonry applications - provides broad approval coverage so the same anchor works across a wide range of structural substrates
• Qualified for static and seismic loading conditions, seismic design categories A through F - covers the full spectrum of seismic risk zones, giving engineers and installers confidence in the most demanding environments
• Chamfered top designed to prevent mushrooming during installation - promotes a clean, consistent set without damaging the anchor head, reducing installation errors on the job site
• Suitable for horizontal, vertical, and overhead applications - offers installation flexibility so a single anchor solution works in multiple orientations without requiring a different product
• Tested per ACI355.2 and AC193 - independently validated performance gives specifiers and inspectors the documentation they need for code-compliant projects
• Installs with a 1/2 in. drill bit and 3/4 in. wrench size - straightforward tooling requirements keep installation simple and accessible with standard equipment

Why This Product

• Built for cracked concrete without sacrificing load performance - the secondary expansion mechanism actively responds to crack formation at the anchor location, making this wedge anchor a dependable choice for concrete that may develop cracks over time rather than requiring a separate specialized product
• Full-range seismic qualification means fewer specification decisions - coverage across seismic design categories A through F eliminates the need to evaluate multiple anchors for different project locations, streamlining the design and procurement process
• Versatile installation orientations reduce product inventory complexity - suitability for horizontal, vertical, and overhead concrete and masonry connections means one anchor handles multiple conditions on the same job, whether for structural framing, mechanical attachments, or overhead supports
• Backed by Simpson engineering and third-party test standards - compliance with ACI355.2 and AC193, combined with code listings for cracked and uncracked concrete, gives contractors and engineers the documentation confidence needed for inspected and permitted structural work

Specifications

• Size: 1/2 in. x 4-3/4 in.
• Manufacturer Part Number (MPN): STB2-50434F25
• Brand: Simpson Strong-Tie
• Diameter: 1/2 in.
• Length: 4-3/4 in.
• Thread Length: 3-1/16 in.
• Material: Carbon Steel
• Coating/Finish: Zinc Plated
• Installation: Installs with 1/2 in. drill bit and 3/4 in. wrench size
• Packaging: Packs of 25 and Cartons of 200
• Drill Bit Diameter: 1/2 in.

Approved Applications

• Cracked concrete
• Uncracked concrete
• Masonry applications
• Horizontal installations
• Vertical installations
• Overhead installations
• Seismic design categories A through F
• High-wind structural connections

Frequently Asked Questions

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

Yes. The Strong-Bolt 2 is code listed for both cracked and uncracked concrete, as well as masonry applications. Its dual undercutting embossments on each clip segment enable secondary expansion should a crack form and intersect the anchor location, helping maintain load capacity even as conditions change.

What seismic design categories is this anchor qualified for?

The Strong-Bolt 2 is qualified for static and seismic loading conditions covering seismic design categories A through F - the full range - making it suitable for the most demanding seismic environments.

What tools are needed to install this wedge anchor?

Installation requires a 1/2 in. drill bit to bore the hole and a 3/4 in. wrench size to tighten the nut. The chamfered top is designed to prevent mushrooming during installation, helping ensure a clean, reliable set.

What standards has the Strong-Bolt 2 been tested to?

The Strong-Bolt 2 has been tested per ACI355.2 and AC193, two widely recognized standards for qualification of post-installed anchors in concrete and masonry.

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