The Simpson Strong-Bolt 2 Wedge Anchor in 1/2 in. x 3-3/4 in. is a high-performance wedge-type expansion anchor engineered by Simpson for demanding concrete fastening applications - including seismic and high-wind environments. Constructed entirely from Type 304 stainless steel, this anchor delivers long-lasting corrosion resistance across a wide range of service environments, making it a reliable choice for both indoor and outdoor concrete anchoring where moisture, chemicals, or harsh conditions are a concern. Whether securing structural fixtures overhead, horizontally, or vertically into cracked or uncracked concrete, this anchor is built to perform where it counts most.

Key Features

• Code listed for cracked and uncracked concrete applications - gives installers confidence the anchor meets building code requirements in both standard and compromised concrete conditions
• Dual undercutting embossments on each clip segment enable secondary expansion should a crack form and intersect the anchor location - significantly increases load-carrying ability if the surrounding hole expands, adding a critical safety margin in real-world conditions
• Qualified for static and seismic loading conditions (seismic design categories A through F) - suitable for use in virtually any seismic zone across the country, reducing the need for project-specific engineering exceptions
• Chamfered top designed to prevent mushrooming during installation - protects the bolt head during driving for a clean, professional installation every time
• Suitable for horizontal, vertical, and overhead applications - gives contractors flexibility to use a single anchor type across multiple orientations on the same job site
• Standard ANSI fractional sizing - fits standard fixtures and installs with common drill bit and tool sizes, minimizing the need for specialty tooling
• Tested per ACI355.2 and AC193 - meets recognized independent testing standards, supporting code compliance documentation
• Made from Type 304 stainless steel - resists rust, oxidation, and corrosion for long service life in wet, outdoor, and chemically active environments
• Fully assembled and ready to install - saves time on the job site with no pre-assembly required

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 suitable for the most demanding structural fastening codes without requiring special engineering approval
• Secondary expansion technology adds a safety net - if a concrete crack forms at the anchor point after installation, the dual undercutting embossments trigger secondary expansion, helping maintain load capacity rather than failing suddenly
• Type 304 stainless steel construction means this anchor resists corrosion in service environments where carbon steel or zinc-plated anchors would deteriorate - ideal for anchoring in areas exposed to moisture, coastal air, or chemical exposure
• Standard ANSI fractional dimensions mean this anchor works with the 1/2 in. drill bits and 3/4 in. wrenches already on most job sites - no proprietary tooling required, reducing setup time and cost

Specifications

• Brand: Simpson Strong-Tie
• Diameter: 1/2 in.
• Length: 3-3/4 in.
• Drill Bit Diameter: 1/2 in.
• Thread Length: 2 1/16 in.
• Material: Type 304 Stainless Steel
• Finish: Type 304 Stainless Steel
• Assembly: Fully Assembled

Available Pack Options

• STB2-503344SS: 25 Pk
• STB2-503344SS -5P: 125 Pk

Install With

• Installs with 1/2 in. drill bit and 3/4 in. wrench size

Frequently Asked Questions

Can the Strong-Bolt 2 be used in cracked concrete?

Yes. The Strong-Bolt 2 is code listed for both cracked and uncracked concrete applications. Its dual undercutting embossments provide secondary expansion if a crack forms and intersects the anchor location, helping the anchor maintain load capacity even in compromised concrete.

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 of seismic categories used in US building codes.

What drill bit size is needed to install this anchor?

A 1/2 in. drill bit is required for installation. A 3/4 in. wrench is used to tighten the nut. These are standard ANSI fractional sizes compatible with common tools and fixtures.

Is this anchor suitable for overhead and horizontal applications?

Yes. The Strong-Bolt 2 is suitable for horizontal, vertical, and overhead applications, providing installation flexibility across a wide range of concrete anchoring projects.

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