The Simpson Strong-Bolt 2 Wedge Anchor (5/8 in. x 5 in., Type 316 Stainless Steel) is a wedge-type expansion anchor engineered for high-performance concrete fastening in demanding structural applications, including seismic and high-wind conditions. Built by Simpson from Type 316 stainless steel throughout, this anchor delivers long-lasting corrosion resistance across a wide variety of service environments. Dual undercutting embossments on each clip segment enable secondary expansion if a crack forms and intersects the anchor location, making it a reliable choice for both cracked and uncracked concrete installations. It installs with a standard 5/8 in. drill bit and a 15/16 in. wrench, keeping the installation process straightforward for contractors and builders alike.

Key Features

• Code listed for cracked and uncracked concrete applications - gives you confidence the anchor meets recognized standards for the widest range of concrete conditions on the job site.
• Dual undercutting embossments on each clip segment - enable secondary expansion if a crack intersects the anchor location, significantly increasing load-carrying ability even as the hole expands.
• Chamfered top design - prevents mushrooming during installation, protecting the threads and making nut removal easier after setting.
• Qualified for static and seismic loading conditions (seismic design categories A through F) - covers the full range of seismic risk zones, so one anchor model works across virtually all project locations.
• Suitable for horizontal, vertical, and overhead applications - provides installation flexibility so the same anchor handles multiple orientations on a single project.
• Standard ANSI fractional sizing - fits standard fixtures and works with common drill bit and tool sizes, reducing the need for specialized equipment.
• Tested per ACI355.2 and AC193 - independently verified performance gives engineers and inspectors the documentation they need for code-compliant submittals.
• Type 316 stainless steel construction throughout - the anchor body, nut, washer, and clip are all 316 stainless, providing consistent corrosion resistance in wet, coastal, and chemically exposed environments.

Why This Product

• Built for worst-case concrete conditions - the secondary expansion capability from the dual undercutting embossments means the anchor does not simply lose holding strength if a crack develops, giving structural professionals added assurance in aging or stressed concrete structures.
• Seismic and high-wind qualified across all design categories - qualification through seismic design categories A through F means this wedge anchor can be specified on projects in even the most demanding seismic zones without substitution or special engineering exceptions.
• All-316 stainless steel for long-term performance - using Type 316 stainless steel for every component, not just the body, reduces the risk of galvanic corrosion at contact points, making this anchor a dependable choice for exterior, marine, or corrosive service environments.
• Installs with common tools and standard drill sizes - the 5/8 in. drill bit and 15/16 in. wrench requirement means no specialized tooling is needed, keeping installation efficient and cost-effective on both small and large-scale projects.

Specifications

• Size: 5/8 in. x 5 in.
• MPN: STB2-62500S6F20
• Brand: Simpson Strong-Tie
• Diameter: 5/8 in.
• Length: 5 in.
• Thread Length: 2-15/16 in.
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• 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
• Installation Drill Bit: 5/8 in.
• Wrench Size: 15/16 in.
• Testing Standards: ACI355.2 and AC193
• Packaging: Packs of 20 and Cartons of 80

Approved Applications

• Cracked concrete fastening applications
• Uncracked concrete fastening applications
• Static loading conditions
• Seismic loading conditions - seismic design categories A through F
• High-wind structural conditions
• Horizontal installations
• Vertical installations
• Overhead installations

Frequently Asked Questions

What makes the Strong-Bolt 2 suitable for cracked concrete?

The Strong-Bolt 2 features dual undercutting embossments on each clip segment that enable secondary expansion should a crack form and intersect the anchor location. This design significantly increases the anchor's ability to carry load even if the hole expands, and the product is code listed for both cracked and uncracked concrete applications.

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

The Strong-Bolt 2 (5/8 in. x 5 in.) installs with a 5/8 in. drill bit and requires a 15/16 in. wrench size for tightening.

Is this anchor approved for seismic applications?

Yes. The Strong-Bolt 2 is qualified for both static and seismic loading conditions, covering seismic design categories A through F, making it an optimal choice for high-performance fastening even in seismic and high-wind conditions.

Why is Type 316 stainless steel used for this anchor?

Type 316 stainless steel is used throughout the entire anchor assembly - including the anchor body, nut, washer, and clip - to provide long-lasting corrosion resistance suitable for a wide variety of demanding service environments where standard carbon steel anchors may be prone to corrosion.

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