The Simpson Strong-Bolt 2 1/2 in. x 3-3/4 in. Wedge Anchor in Type 316 Stainless Steel is a wedge-type expansion anchor engineered for high-performance concrete anchoring in the most demanding conditions. Built from Type 316 stainless steel throughout - anchor body, nut, washer, and clip - it delivers long-lasting corrosion resistance across a wide variety of service environments. Qualified for both static and seismic loading, and code listed for cracked and uncracked concrete alike, this anchor is an optimal choice wherever structural reliability and material durability are non-negotiable.

Key Features

• Dual undercutting embossments on each clip segment - enable secondary expansion if a crack forms and intersects the anchor location, significantly increasing load-carrying capacity even when the hole expands in cracked concrete conditions
• Code listed for cracked and uncracked concrete applications - gives engineers and installers the documentation confidence needed for permitted and inspected work
• Qualified for seismic design categories A through F and high-wind conditions - makes this wedge anchor suitable for the full range of seismic zones, including the most demanding structural environments
• Chamfered top design - prevents mushrooming during installation, protecting thread integrity and ensuring a clean, reliable fit every time
• Suitable for horizontal, vertical, and overhead applications - provides installation flexibility across orientations without requiring separate anchor specifications
• Standard ANSI fractional sizing at 1/2 in. diameter - installs with a common 1/2 in. drill bit and 3/4 in. wrench, minimizing the need for specialty tooling on the job site
• Tested per ACI 355.2 and AC193 - independently verified performance data supports use in code-governed projects requiring traceable anchor qualification
• All components manufactured from Type 316 stainless steel - provides consistent corrosion resistance across every part of the assembly, ideal for moisture-exposed or corrosive service environments

Why This Product

• Built for cracked concrete without compromise - the dual undercutting embossments allow the anchor to maintain load capacity even after cracking intersects the anchor hole, a critical advantage in seismic zones and aging concrete structures where standard wedge anchors can lose holding power
• Full 316 stainless steel assembly from top to bottom - because every component including the clip, washer, and nut shares the same Type 316 material, there is no weak link in corrosion resistance, making it a dependable choice for exterior, coastal, or chemically exposed installations
• Seismic and wind qualification across all design categories - with coverage from seismic design categories A through F, this anchor eliminates the need to source a different product for high-seismic projects, simplifying procurement and keeping installations code-compliant
• Installs with standard tooling - the 1/2 in. drill bit requirement and ANSI fractional sizing mean crews can work with common equipment already on hand, reducing setup time and keeping projects on schedule

Specifications

• Model Number: STB2-50334S6F25
• Size: 1/2 in. x 3-3/4 in.
• Anchor Size: 1/2 in. x 3-3/4 in.
• Coating/Material: Type 316 Stainless Steel
• Drill Bit Diameter: 1/2 in.
• Thread Length: 2-1/16 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 25 and Cartons of 125

Approved Applications

• Cracked concrete installations
• Uncracked concrete installations
• Seismic applications requiring code-listed anchoring solutions
• High-wind condition installations requiring high-performance anchorage
• Corrosive or moisture-exposed service environments where stainless steel is required

Frequently Asked Questions

Is the Strong-Bolt 2 STB2-50334S6F25 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 allow for secondary expansion if a crack forms and intersects the anchor location, significantly increasing load-carrying capacity even when the hole expands.

What drill bit size is required to install the STB2-50334S6F25?

Installation requires a 1/2 in. diameter drill bit, matching the anchor's 1/2 in. diameter.

Why is Type 316 stainless steel used for all components of this anchor?

Type 316 stainless steel is used for the anchor body, nut, washer, and clip to provide long-lasting corrosion resistance across a wide variety of service environments, making this anchor suitable for applications 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 anchor is specifically noted as an optimal choice for high-performance applications, including those in seismic and high-wind conditions, and is code listed accordingly.

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