The Simpson Strong-Bolt 2 1/4 in. x 3-1/4 in. Wedge Anchor in Type 304 Stainless Steel is a wedge-type expansion anchor engineered for high-performance concrete fastening in the most demanding conditions. Built entirely from Type 304 Stainless Steel - anchor body, nut, and washer included - this anchor delivers long-lasting corrosion resistance across a wide variety of service environments, making it a dependable solution wherever moisture, chemicals, or other corrosive conditions are present. Qualified for both static and seismic loading and tested per ACI 355.2 and AC193, the Strong-Bolt 2 is a trusted choice for structural anchoring professionals working in seismic and high-wind zones.

Key Features

• Type 304 Stainless Steel construction throughout - the anchor body, nut, and washer are all manufactured from Type 304 Stainless Steel (clip from Type 304 or Type 316 Stainless Steel), providing superior corrosion resistance for long-term performance in harsh or moisture-exposed environments.
• Dual undercutting embossments on each clip segment - enables secondary expansion if a crack forms and intersects the anchor location, significantly increasing the anchor's ability to carry load even when the hole expands.
• Qualified for seismic design categories A through F - covers the full range of seismic risk classifications, giving engineers and contractors the code confidence needed for structural installations in earthquake-prone and high-wind regions.
• Chamfered top design - prevents mushrooming of the anchor during installation, resulting in cleaner, more consistent installs and reducing the risk of installation error.
• Suitable for horizontal, vertical, and overhead applications - offers installation flexibility across orientations, reducing the need for multiple anchor types on a single job site.
• Installs with a standard 1/4 in. drill bit and 7/16 in. wrench - compatible with common tooling already on site, keeping installation straightforward and efficient.
• Tested per ACI 355.2 and AC193 - independently evaluated to recognized industry standards, supporting use in code-compliant structural and construction applications.

Why This Product

• Built for cracked and uncracked concrete alike - the dual undercutting embossments on each clip segment provide secondary expansion when cracks intersect the anchor, making the Strong-Bolt 2 a reliable choice for applications where concrete integrity cannot be fully guaranteed in advance.
• Full stainless steel assembly for corrosive environments - with the anchor body, nut, and washer all in Type 304 Stainless Steel and the clip in Type 304 or Type 316 Stainless Steel, this anchor is purpose-built for service environments where carbon steel fasteners would deteriorate prematurely.
• Seismic and high-wind rated across all design categories - qualification for seismic design categories A through F means a single anchor solution works across virtually any project requiring code-listed seismic performance, simplifying specification and procurement.
• Versatile installation orientations - approved for horizontal, vertical, and overhead use, this wedge anchor adapts to the varied demands of structural, mechanical, and general construction fastening without requiring application-specific alternatives.

Specifications

• Model No.: STB2-25314S4F100
• Coating/Material: Type 304 Stainless Steel
• Size (in.): 1/4 in. x 3-1/4 in.
• Drill Bit Diameter (in.): 1/4 in.
• Thread Length (in.): 2-7/16 in.
• Component Material, Anchor Body: Type 304 Stainless Steel
• Component Material, Nut: Type 304 Stainless Steel
• Component Material, Washer: Type 304 Stainless Steel
• Component Material, Clip: Type 304 or Type 316 Stainless Steel
• Packaging: Packs of 100 and Cartons of 500

Approved Applications

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

Frequently Asked Questions

Is the Strong-Bolt 2 (STB2-25314S4F100) 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 on each clip segment enable secondary expansion should a crack form and intersect the anchor location, significantly increasing its ability to carry load even if the hole expands.

What drill bit size is required to install this anchor?

A 1/4-inch diameter drill bit is required to install the STB2-25314S4F100 Strong-Bolt 2 wedge anchor.

Why is stainless steel specified for this anchor?

The anchor body, nut, and washer are all manufactured from Type 304 Stainless Steel, and the clip from Type 304 or Type 316 Stainless Steel. This all-stainless construction provides long-lasting corrosion resistance for a wide variety of service environments where exposure to moisture or corrosive conditions is a concern.

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

Yes. The Strong-Bolt 2 wedge-type expansion anchor is code listed and considered an optimal choice for high-performance use 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.