The Simpson Strong-Bolt 2 Wedge Anchor (5/8 in. x 8-1/2 in., Type 316 Stainless Steel) is a wedge-type expansion anchor built for high-performance structural connections in both cracked and uncracked concrete. Engineered by Simpson to perform reliably under seismic and high-wind conditions, this anchor features dual undercutting embossments on each clip segment that enable secondary expansion should a crack form and intersect the anchor location - significantly increasing load-carrying ability when the hole expands. Constructed entirely from Type 316 stainless steel, it delivers long-lasting corrosion resistance across a wide variety of demanding service environments.

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 jobsite.
• Dual undercutting embossments on each clip segment enable secondary expansion - maintains load capacity if a crack forms and intersects the anchor, adding a critical layer of structural reliability.
• Qualified for static and seismic loading conditions (seismic design categories A through F) - makes this anchor suitable for high-risk seismic zones where code compliance is non-negotiable.
• Chamfered top designed to prevent mushrooming during installation - protects the anchor head for a cleaner, more secure installation with less risk of damage.
• Suitable for horizontal, vertical and overhead applications - provides installation flexibility across a broad range of structural anchoring scenarios without needing a different product.
• Standard (ANSI) fractional sizes installs with a 5/8 in. drill bit and 15/16 in. wrench - works with common drill bit and tool sizes already on hand, reducing setup time and tooling costs.
• Made from Type 316 stainless steel throughout - resists corrosion in moisture-exposed and chemically aggressive environments where standard carbon steel hardware would fail prematurely.
• Tested per ACI355.2 and AC193 - independently verified performance gives engineers and contractors the documentation needed to specify with confidence.

Why This Product

• Built for seismic and high-wind performance - the Strong-Bolt 2 is qualified for seismic design categories A through F and engineered for both static and dynamic loading conditions, making it one of the most versatile concrete wedge anchors available for code-sensitive structural work.
• Secondary expansion technology protects load capacity in cracked concrete - unlike basic expansion anchors, the dual undercutting embossments on each clip segment allow the anchor to re-engage and continue carrying load if the surrounding concrete cracks, a meaningful safety advantage in real-world conditions.
• Type 316 stainless steel construction resists corrosion where it matters most - with the nut, washer, clip, and anchor body all made from Type 316 stainless steel, this anchor is purpose-built for corrosive, wet, or marine-adjacent environments where long-term fastener integrity is critical.
• Installs with standard tooling and fits common fixtures - ANSI fractional sizing means no special equipment is required, keeping installation straightforward and compatible with existing hardware and structural fixtures on the job.

Specifications

• Size: 5/8 in. x 8-1/2 in.
• Manufacturer: Simpson Strong-Tie
• MPN: STB2-62812S6F20
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Diameter: 5/8 in.
• Length: 8-1/2 in.
• Thread Length: 6 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
• Required Drill Bit: 5/8 in.
• Required Wrench Size: 15/16 in.
• Testing Standards: ACI355.2 and AC193
• Packaging: Packs of 20 and Cartons of 40

Approved Applications

• Cracked concrete structural connections
• Uncracked concrete structural connections
• Seismic design categories A through F installations
• High-wind condition structural anchoring
• Horizontal anchor installations
• Vertical anchor installations
• Overhead anchor installations
• Corrosive or moisture-exposed service environments requiring stainless-steel hardware

Frequently Asked Questions

What drill bit size is required to install the Strong-Bolt 2 5/8 in. wedge anchor?

The Strong-Bolt 2 5/8 in. x 8-1/2 in. wedge anchor installs with a standard 5/8 in. drill bit and requires a 15/16 in. wrench for tightening, making it compatible with common drill bit and tool sizes.

Is this wedge anchor rated for seismic applications?

Yes. The Strong-Bolt 2 is qualified for both static and seismic loading conditions and is code listed for seismic design categories A through F. Its dual undercutting embossments on each clip segment enable secondary expansion if a crack forms and intersects the anchor location, significantly increasing load-carrying capacity under dynamic conditions.

Can this anchor be used in cracked concrete?

Yes. The Strong-Bolt 2 is code listed for both cracked and uncracked concrete applications. The dual undercutting clip design allows the anchor to maintain load capacity even if the surrounding concrete develops cracks at the anchor location.

Why is Type 316 stainless steel used for this anchor?

Type 316 stainless steel provides superior corrosion resistance compared to standard carbon steel or Type 304 stainless steel, making this anchor well-suited for a wide variety of demanding service environments where long-term durability and resistance to corrosion are critical requirements. All components - including the anchor body, nut, washer, and clip - are manufactured from Type 316 stainless steel.

Note: Product dimensions and/or thread length may differ from picture. Please refer to the specifications listed above for exact dimensions.