The Simpson Strong-Bolt 2 1/2 in. x 5-1/2 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 conditions. Designed by Simpson to excel in seismic and high-wind environments, this anchor features dual undercutting embossments on each clip segment that enable secondary expansion if a crack forms and intersects the anchor location - significantly improving load-carrying capacity when the hole expands. Whether you are anchoring into cracked or uncracked concrete in horizontal, vertical, or overhead orientations, this stainless-steel wedge anchor delivers dependable holding power backed by rigorous code compliance and corrosion-resistant construction.

Key Features

• Code listed for cracked and uncracked concrete applications - gives you the flexibility to use a single anchor solution across a wide range of structural conditions without second-guessing code compliance.
• Dual undercutting embossments on each clip segment - enable secondary expansion if a crack intersects the anchor, maintaining load-carrying performance even as base material conditions change.
• Chamfered top designed to prevent mushrooming during installation - protects the thread integrity as you drive the anchor, resulting in a cleaner, more reliable installation every time.
• Qualified for static and seismic loading conditions (seismic design categories A through F) - meets the highest seismic performance demands, making it suitable for critical structural connections in earthquake-prone and high-wind regions.
• Suitable for horizontal, vertical, and overhead applications - provides installation versatility so one anchor covers multiple orientations on the same job site.
• Made from Type 316 stainless steel throughout - delivers long-lasting corrosion resistance across a wide variety of service environments, including areas exposed to moisture or corrosive elements.
• Standard ANSI fractional sizing - fits standard fixtures and installs with a common 1/2 in. drill bit and 3/4 in. wrench, minimizing the need for specialized tooling.
• Tested per ACI355.2 and AC193 - independently validated performance gives engineers and inspectors confidence in specified load values and code acceptance.

Why This Product

• Built for seismic and high-wind structural work - the Strong-Bolt 2 is qualified for seismic design categories A through F and high-wind structural connections, making it one of the most broadly approved wedge anchors available for critical concrete fastening applications.
• Secondary expansion technology protects your connection - the dual undercutting embossments on each clip segment activate if the concrete cracks at the anchor location, giving the anchor a second opportunity to expand and hold load rather than simply losing capacity.
• Type 316 stainless steel construction resists corrosion for the long term - every component - body, nut, washer, and clip - is Type 316 stainless steel, making this concrete anchor well suited for exterior, coastal, chemical-exposure, and other corrosive service environments where carbon steel alternatives would degrade.
• Straightforward installation with common tools - ANSI fractional sizing means this 1/2 in. wedge anchor pairs directly with a standard 1/2 in. drill bit and 3/4 in. wrench, reducing setup time and keeping your workflow moving on both new construction and retrofit anchoring projects.

Specifications

• Size: 1/2 in. x 5-1/2 in.
• MPN: STB2-50512S6F25
• Brand: Simpson Strong-Tie
• Anchor Type: Wedge-Type Expansion Anchor
• Diameter: 1/2 in.
• Length: 5-1/2 in.
• Thread Length: 3-13/16 in.
• Material - Anchor Body: Type 316 Stainless Steel
• Material - Nut: Type 316 Stainless Steel
• Material - Washer: Type 316 Stainless Steel
• Material - Clip: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Installation - Drill Bit Size: 1/2 in.
• Installation - Wrench Size: 3/4 in.
• Assembly: Fully Assembled
• Packaging: Packs of 25 and Cartons of 50

Approved Applications

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

Frequently Asked Questions

What type of concrete can the Strong-Bolt 2 be used in?

The Strong-Bolt 2 is code listed for both cracked and uncracked concrete applications, providing versatile performance across a broad range of structural conditions.

Why is Type 316 stainless steel used for this anchor?

Type 316 stainless steel offers long-lasting corrosion resistance for a wide variety of service environments, making this anchor well-suited for applications where exposure to moisture, chemicals, or other corrosive elements is a concern.

What tools are needed to install the Strong-Bolt 2 1/2 in. x 5-1/2 in. anchor?

Installation requires a 1/2 in. drill bit to bore the hole and a 3/4 in. wrench to tighten the nut. The chamfered top is designed to prevent mushrooming during installation, helping ensure a clean and secure set.

Is the Strong-Bolt 2 approved for seismic applications?

Yes. The Strong-Bolt 2 is qualified for static and seismic loading conditions covering seismic design categories A through F. Its dual undercutting embossments on each clip segment enable secondary expansion should a crack form and intersect the anchor location, significantly increasing the ability of Strong-Bolt 2 to carry load if the hole expands.

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