Simpson Strong-Bolt 2 Wedge Anchor - 3/8 in. x 5 in. - Type 304 Stainless Steel is a high-performance expansion anchor engineered for demanding concrete fastening applications, including those subject to seismic activity and high-wind conditions. Built from Type 304 stainless steel throughout, this wedge-type anchor delivers long-lasting corrosion resistance across a wide range of service environments - making it a reliable choice wherever moisture, chemicals, or outdoor exposure are a concern. The innovative dual undercutting embossments on each clip segment allow for secondary expansion if a crack forms and intersects the anchor, giving the anchor the ability to continue carrying load even as the hole expands. Whether securing structural elements to cracked or uncracked concrete, this anchor from Simpson provides consistent, code-listed performance.

Key Features

• Code listed for cracked and uncracked concrete applications - gives engineers and inspectors confidence that the anchor meets recognized standards for both crack-prone and stable concrete conditions
• Dual undercutting embossments on each clip segment enable secondary expansion - allows the anchor to maintain load capacity if a crack forms and intersects the anchor location, adding a critical safety margin
• 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 for project-specific engineering exceptions
• Chamfered top designed to prevent mushrooming during installation - ensures a cleaner, more consistent installation without damaging the anchor head
• Suitable for horizontal, vertical, and overhead applications - provides installation flexibility for a wide variety of structural and mechanical fastening needs
• Standard ANSI fractional sizing at 3/8 in. diameter - fits standard fixtures and works with common drill bits and tools, keeping installation simple and cost-effective
• Made from Type 304 stainless steel - provides excellent corrosion resistance in wet, coastal, and chemically exposed environments where carbon steel anchors would degrade
• Tested per ACI 355.2 and AC193 - independently verified performance gives buyers assurance of load ratings under recognized test protocols

Why This Product

• Designed for seismic and high-wind environments - the secondary expansion feature and qualification across seismic design categories A through F make this anchor a practical solution for projects in earthquake-prone or storm-exposed regions where standard anchors may not be code-acceptable
• Type 304 stainless steel construction throughout - where carbon steel or zinc-plated anchors would corrode over time in wet or chemically active environments, the all-stainless build of this anchor supports long service life with minimal maintenance
• Works in cracked concrete - unlike many expansion anchors that are only rated for uncracked concrete, the Strong-Bolt 2 is code listed for cracked concrete applications, expanding the range of substrates where it can be confidently specified
• Versatile installation orientation - horizontal, vertical, and overhead compatibility means this single anchor type can serve multiple connection points on a project without requiring different products for different orientations

Specifications

• Brand: Simpson Strong-Tie
• Diameter: 3/8 in.
• Length: 5 in.
• Thread Length: 3 9/16 in.
• Drill Bit Diameter: 3/8 in.
• Material: Type 304 Stainless Steel
• Finish: Type 304 Stainless Steel

Available Pack Options

• STB2-375004SS: 50 Pk
• STB2-375004SS -4P: 200 Pk

Install With

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

Frequently Asked Questions

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

Yes. This anchor is code listed for both cracked and uncracked concrete applications. The dual undercutting embossments on each clip segment enable secondary expansion if a crack intersects the anchor location, allowing the anchor to continue carrying 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 - the full range recognized under U.S. building codes - making it appropriate for high-seismic regions as well as standard construction.

What drill bit and wrench size are needed to install this anchor?

Installation requires a 3/8 in. drill bit and a 9/16 in. wrench. The anchor uses standard ANSI fractional sizing, so it works with common drill bits and tools without the need for specialized equipment.

Can this anchor be used in overhead and horizontal applications, or only vertical installations?

This anchor is suitable for horizontal, vertical, and overhead applications, providing flexibility for a wide variety of structural and mechanical fastening configurations in concrete.