The Simpson Strong-Bolt 2 3/8 in. x 3-3/4 in. Wedge Anchor is a wedge-type expansion anchor from Simpson built for high-performance concrete and masonry fastening in the most demanding structural environments. Engineered to hold reliably in seismic and high-wind conditions, it incorporates dual undercutting embossments on each clip segment to enable secondary expansion should a crack form and intersect the anchor location - significantly increasing the ability of the anchor to carry load even as the hole expands. Available in zinc-plated carbon steel, mechanically galvanized carbon steel, and Type 304 and Type 316 stainless steel, this anchor delivers tested, code-listed performance across a wide range of installation scenarios.

Key Features

• Code listed for cracked and uncracked concrete, and masonry applications - gives contractors and inspectors confidence that the anchor meets recognized code requirements across a broad range of substrate conditions.
• Dual undercutting embossments on each clip segment enable secondary expansion - if a crack forms and intersects the anchor location, the anchor continues to carry load rather than losing holding strength, making it a reliable choice for concrete structures subject to stress or movement.
• Chamfered top designed to prevent mushrooming during installation - protects the threads during hammer setting so the nut runs on cleanly every time, reducing installation errors and rework.
• Qualified for static and seismic loading conditions, seismic design categories A through F - covers the full spectrum of seismic risk zones, so a single anchor specification works on projects from low-risk to the most seismically active regions.
• Suitable for horizontal, vertical, and overhead applications - provides installation flexibility across orientations, eliminating the need to stock separate anchors for different structural attachment scenarios.
• Tested per ACI355.2 and AC193 - independently verified performance gives engineers and inspectors the documentation they need for code-compliant submittals and inspections.
• Installs with a 3/8 in. drill bit and 9/16 in. wrench - straightforward tooling requirements mean no specialized equipment is needed on the job site.

Why This Product

• Built for cracked concrete without compromise - the secondary expansion mechanism provided by the dual undercutting embossments means this wedge anchor maintains load-carrying capacity even if the concrete cracks at the anchor point, a critical advantage over standard expansion anchors in structural and seismic applications.
• Full seismic coverage from a single anchor - qualification across seismic design categories A through F means this concrete fastener meets seismic requirements on virtually any project site, streamlining product selection and specification for engineers and contractors alike.
• Versatile across substrates and orientations - code listing for cracked concrete, uncracked concrete, and masonry, combined with suitability for vertical, horizontal, and overhead installations, makes this a go-to wedge anchor for a wide variety of structural fastening tasks on a single job.
• Tested and code-listed performance you can document - with testing per ACI355.2 and AC193, this anchor comes backed by third-party verified data, giving project teams the technical support needed to satisfy inspections and meet strict structural fastening requirements.

Specifications

• Size: 3/8 in. x 3-3/4 in.
• Manufacturer Part Number (MPN): STB2-37334F50
• Brand: Simpson Strong-Tie
• Material: Carbon Steel
• Coating: Zinc Plated
• Finish: Zinc Plated
• Diameter: 3/8 in.
• Length: 3-3/4 in.
• Thread Length: 2-5/16 in.
• Installation Drill Bit: 3/8 in.
• Wrench Size: 9/16 in.
• Packaging: Packs of 50 and Cartons of 250

Approved Applications

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

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, as well as masonry applications. Its dual undercutting embossments on each clip segment allow for secondary expansion if a crack forms and intersects the anchor location, helping the anchor continue to carry load even as the hole expands.

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 - making it suitable for use in the most demanding seismic environments.

What tools are needed to install the Strong-Bolt 2?

Installation requires a 3/8 in. drill bit to bore the hole and a 9/16 in. wrench to tighten the anchor once inserted.

What standards was this anchor tested to?

The Strong-Bolt 2 has been tested per ACI355.2 and AC193, ensuring it meets rigorous performance criteria for wedge-type expansion anchors in concrete and masonry.

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