The Simpson Strong-Bolt 2 Wedge Anchor in 3/8 in. x 3 in. by Simpson is a heavy-duty expansion anchor engineered for high-performance concrete fastening in demanding structural applications - including seismic zones and high-wind environments. Constructed entirely from Type 304 stainless steel, this wedge-type expansion anchor delivers long-lasting corrosion resistance suited for a wide range of challenging service environments, both indoors and out. With code listings for cracked and uncracked concrete and qualification across all seismic design categories (A through F), this stainless steel concrete anchor is a reliable choice for engineers, contractors, and builders who need a dependable hold in critical applications.

Key Features

• Code listed for cracked and uncracked concrete applications - gives installers and engineers confidence that the anchor meets recognized standards for both intact and structurally compromised concrete
• Dual undercutting embossments on each clip segment enable secondary expansion if a crack forms and intersects the anchor - significantly increases load-carrying capacity even when the drilled hole expands over time
• Chamfered top design prevents mushrooming during installation - makes driving the anchor cleaner and faster, reducing potential installation errors
• Qualified for static and seismic loading conditions across seismic design categories A through F - suitable for use in virtually any seismic zone in the United States
• Suitable for horizontal, vertical, and overhead applications - provides installation flexibility for a broad range of structural and mechanical fastening tasks
• Standard ANSI fractional sizing (3/8 in. x 3 in.) - fits standard fixtures and installs with common drill bit and tool sizes, reducing the need for specialty equipment
• Tested per ACI 355.2 and AC193 - independently verified performance gives specifiers and inspectors documented proof of anchor capability
• Made from Type 304 stainless steel - resists corrosion across a wide variety of service environments, including damp, humid, and mildly corrosive conditions
• Fully assembled out of the box - ready to install immediately, saving setup time on the job site

Why This Product

• Built for seismic and high-wind zones - the Strong-Bolt 2 is qualified for seismic design categories A through F, making it one of the few wedge anchors appropriate for use in the most demanding seismic environments without requiring special engineered substitutions
• Secondary expansion technology adds a safety margin - dual undercutting embossments on each clip allow the anchor to continue carrying load even if a concrete crack intersects the installation point, a critical advantage in aging or stressed concrete structures
• Type 304 stainless steel construction resists corrosion in environments where standard carbon steel anchors would degrade - suitable for humid interiors, coastal-adjacent projects, and other corrosion-prone service conditions
• Versatile installation orientation - horizontal, vertical, and overhead use means one anchor solution covers multiple fastening scenarios on the same project, simplifying procurement and on-site logistics

Specifications

• Brand: Simpson Strong-Tie
• Diameter: 3/8 in.
• Length: 3 in.
• Thread Length: 1 9/16 in.
• Drill Bit Diameter: 3/8 in.
• Material: Type 304 Stainless Steel
• Finish: Type 304 Stainless Steel
• Testing Standards: ACI 355.2 and AC193

Available Pack Options

• STB2-373004SS: 50 Pk
• STB2-373004SS -5P: 250 Pk

Install With

• Installs with 3/8 in. drill bit and 9/16 in. wrench size

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 applications. Its dual undercutting embossments allow secondary expansion if a crack forms at the anchor location, helping maintain load-carrying capacity in compromised concrete.

What seismic design categories is the Strong-Bolt 2 qualified for?

The Strong-Bolt 2 is qualified for static and seismic loading conditions across seismic design categories A through F - covering the full range of seismic zones recognized in U.S. building codes.

Can this anchor be used in overhead or horizontal installations?

Yes. The Strong-Bolt 2 is suitable for horizontal, vertical, and overhead applications, making it a versatile concrete fastening solution for a wide variety of structural orientations.

What tools are needed to install the Strong-Bolt 2 3/8 in. x 3 in. anchor?

Installation requires a 3/8 in. drill bit to prepare the hole and a 9/16 in. wrench to tighten the anchor. Standard ANSI fractional sizing means these are common tool sizes readily available to most contractors and installers.