The Simpson Strong-Bolt 2 Wedge Anchor in 3/8 in. x 3-3/4 in. by Simpson is a high-performance wedge-type expansion anchor engineered for demanding concrete fastening applications - including seismic and high-wind conditions. Constructed entirely from Type 304 stainless steel, this expansion anchor delivers long-lasting corrosion resistance across a wide variety of service environments, making it a reliable choice for both interior and exterior concrete anchoring tasks. Whether you are securing structural elements in cracked or uncracked concrete, or working in corrosive conditions where carbon steel hardware would fall short, the Strong-Bolt 2 delivers the strength and durability professionals depend on.

Key Features

• Dual undercutting embossments on each clip segment enable secondary expansion if a crack forms and intersects the anchor location - significantly increases load-carrying capacity even when the hole expands around the anchor
• Code listed for cracked and uncracked concrete applications - gives engineers and inspectors confidence that the anchor meets recognized building code requirements in a variety of concrete conditions
• Qualified for static and seismic loading conditions (seismic design categories A through F) - suitable for structures in earthquake-prone regions and high-wind areas where anchor performance under dynamic loads is critical
• Chamfered top designed to prevent mushrooming during installation - protects the anchor threads and makes nut seating faster and more reliable
• Suitable for horizontal, vertical, and overhead applications - provides installation flexibility across a wide range of structural and architectural anchoring tasks
• Type 304 stainless steel construction throughout - resists corrosion in wet, humid, and chemically active environments where standard carbon steel anchors would degrade
• Standard ANSI fractional sizing at 3/8 in. diameter - fits standard fixtures and installs with common 3/8 in. drill bits and widely available tools, reducing setup time on the job
• Tested per ACI 355.2 and AC193 - independent testing to recognized standards gives confidence in published load values and code compliance

Why This Product

• Built for seismic and high-wind zones - the dual undercutting clip design provides secondary expansion if concrete cracks, so the anchor continues to carry load rather than losing grip when conditions change around it
• Type 304 stainless steel throughout the anchor body, nut, washer, and clip means this fastener is suited for corrosive or moisture-exposed environments where long service life matters and hardware replacement would be costly or difficult
• Versatile installation orientation - horizontal, vertical, and overhead use means one anchor covers multiple anchoring scenarios on a single jobsite, reducing the need for multiple fastener types
• Code-listed for both cracked and uncracked concrete with seismic design category A through F qualification - simplifies the specification and approval process for engineers, contractors, and inspectors working on code-compliant projects

Specifications

• Brand: Simpson Strong-Tie
• Diameter: 3/8 in.
• Length: 3-3/4 in.
• Drill Bit Diameter: 3/8 in.
• Thread Length: 2-5/16 in.
• Material: Type 304 Stainless Steel
• Finish: Type 304 Stainless Steel
• Testing Standards: ACI 355.2 and AC193

Available Pack Options

• STB2-373344SS: 50 Pk
• STB2-373344SS -5P: 250 Pk

Install With

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

Frequently Asked Questions

Is this anchor approved for use in cracked concrete?

Yes. The Strong-Bolt 2 is code listed for both cracked and uncracked concrete applications. The dual undercutting embossments on each clip segment allow the anchor to expand a second time if a crack forms at the anchor location, helping it maintain load capacity even as the concrete condition changes.

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

The Strong-Bolt 2 is qualified for static and seismic loading conditions covering seismic design categories A through F - the full range recognized under building codes - making it appropriate for use in the most seismically active regions.

Why use a stainless steel wedge anchor instead of a standard carbon steel version?

Type 304 stainless steel provides long-lasting corrosion resistance for a wide variety of service environments. Where moisture, humidity, chemicals, or outdoor exposure would cause carbon steel to corrode and lose strength over time, the stainless steel construction of the Strong-Bolt 2 maintains its integrity and appearance throughout its service life.

Can this anchor be installed in an overhead orientation?

Yes. The Strong-Bolt 2 is suitable for horizontal, vertical, and overhead applications, giving installers the flexibility to use it in a variety of anchoring positions without needing a different anchor type for each orientation.

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