The Simpson Strong-Bolt 2 1/4 in. x 3 1/4 in. Wedge Anchor in Type 316 Stainless Steel is a wedge-type expansion anchor engineered for high-performance concrete anchoring in the most demanding structural and environmental conditions. Featuring dual undercutting embossments on each clip segment, this anchor achieves secondary expansion should a crack form and intersect the anchor location - significantly increasing its ability to carry load if the hole expands. With all components manufactured from Type 316 stainless steel, this anchor delivers long-lasting corrosion resistance across a wide variety of service environments, making it a reliable solution for seismic zones, high-wind applications, and corrosive or moisture-prone conditions.

Key Features

• Type 316 stainless steel construction throughout - the anchor body, nut, washer, and clip are all manufactured from Type 316 stainless steel, providing long-lasting corrosion resistance for a wide variety of service environments, including coastal and chemical-exposure settings.
• Dual undercutting embossments on each clip segment - enable secondary expansion if a crack forms and intersects the anchor location, significantly increasing load-carrying capability even when the hole expands.
• Qualified for static and seismic loading conditions (seismic design categories A through F) - gives engineers and contractors confidence to specify this anchor on code-sensitive projects in seismic and high-wind regions.
• Code listed for uncracked concrete applications - provides the documentation required for permitted work and inspections, reducing approval delays on the job site.
• Chamfered top designed to prevent mushrooming during installation - keeps the anchor head intact through the driving process, ensuring a clean, secure set every time.
• Suitable for horizontal, vertical, and overhead applications - delivers reliable performance regardless of installation orientation, increasing versatility across different structural anchoring tasks.
• Standard ANSI fractional sizing - fits standard fixtures and installs with common drill bit and tool sizes, reducing the need for specialized equipment on site.
• Installs with a 1/4 in. drill bit and 7/16 in. wrench - matches tools most crews already carry, streamlining installation and minimizing setup time.
• Tested per ACI355.2 and AC193 - independent third-party testing against recognized industry standards confirms consistent, predictable performance for critical structural connections.

Why This Product

• Built for cracked and seismic conditions where other anchors fall short - the dual undercutting clip embossments provide secondary expansion in cracked concrete, and the anchor is qualified for seismic design categories A through F, making it one of the few wedge anchors suited for the full range of structural and seismic demands.
• All-stainless construction protects the entire fastener assembly - because the anchor body, nut, washer, and clip are all Type 316 stainless steel, there are no mixed-material weak points that can corrode and compromise the connection over time in harsh or moisture-prone environments.
• Installs with standard tools and no learning curve - ANSI fractional sizing means no specialty drill bits or adapters are required, so crews can set these anchors quickly using equipment already on the truck.
• Third-party tested and code listed for permitted work - testing per ACI355.2 and AC193 provides the documented performance data inspectors and plan reviewers require, helping projects move through approval without unnecessary back-and-forth.

Specifications

• Model Number: STB2-25314S6F100
• Coating/Material: Type 316 Stainless Steel
• Size: 1/4 in. x 3-1/4 in.
• Drill Bit Diameter: 1/4 in.
• Thread Length: 2-7/16 in.
• Anchor Body Material: Type 316 Stainless Steel
• Nut Material: Type 316 Stainless Steel
• Washer Material: Type 316 Stainless Steel
• Clip Material: Type 316 Stainless Steel
• Packaging: Packs of 100 and Cartons of 500

Approved Applications

• Cracked concrete anchoring applications
• Uncracked concrete anchoring applications
• Seismic zone installations
• High-wind condition installations
• Corrosive or moisture-prone service environments

Frequently Asked Questions

Is the Strong-Bolt 2 (STB2-25314S6F100) suitable for use in cracked concrete?

Yes. The Strong-Bolt 2 is code listed for both cracked and uncracked concrete applications. Its dual undercutting embossments on each clip segment enable secondary expansion should a crack form and intersect the anchor location, significantly increasing its ability to carry load if the hole expands.

What material is this wedge anchor made from?

All components - including the anchor body, nut, washer, and clip - are manufactured from Type 316 stainless steel, providing long-lasting corrosion resistance for a wide variety of service environments.

What drill bit diameter is required to install this anchor?

Installation requires a 1/4 in. diameter drill bit, which matches the anchor size of 1/4 x 3-1/4 in.

Can this anchor be used in seismic or high-wind applications?

Yes. The Strong-Bolt 2 wedge-type expansion anchor is specifically noted as an optimal choice for high-performance applications even in seismic and high-wind conditions.

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