The Simpson Strong-Bolt 2 Wedge Anchor (3/8 in. x 2-3/4 in., Type 316 Stainless Steel) is a wedge-type expansion anchor engineered by Simpson for high-performance concrete fastening in some of the most demanding structural conditions, including seismic and high-wind environments. Dual undercutting embossments on each clip segment enable secondary expansion should a crack form and intersect the anchor location, significantly increasing the ability of the Strong-Bolt 2 to carry load if the hole expands. Built entirely from Type 316 stainless steel, this concrete wedge anchor delivers long-lasting corrosion resistance across a wide variety of service environments, making it a dependable choice for both interior and corrosive-exposure applications.

Key Features

• Code listed for cracked and uncracked concrete applications - gives contractors and engineers confidence that the anchor meets recognized code requirements across the full range of concrete fastening conditions.
• Qualified for static and seismic loading conditions (seismic design categories A through F) - covers the entire spectrum of seismic design categories, so this anchor is approved for use in high-seismic zones as well as standard structural applications.
• Dual undercutting embossments on each clip segment - enable secondary expansion if a crack intersects the anchor, helping the fastener maintain load capacity even as concrete conditions change.
• Chamfered top designed to prevent mushrooming during installation - protects the anchor head during driving, reducing installation errors and rework on the job site.
• Suitable for horizontal, vertical, and overhead applications - provides flexibility to anchor into concrete in virtually any orientation without requiring a different product.
• Standard (ANSI) fractional sizes - fits standard fixtures and installs with common drill bit and tool sizes, minimizing the need for specialty equipment.
• Installs with a 3/8 in. drill bit and 9/16 in. wrench - straightforward tooling requirements speed up installation and reduce setup time in the field.
• Tested per ACI355.2 and AC193 - independently verified performance data supports code submissions and engineering documentation.
• Made from Type 316 stainless steel throughout - the anchor body, nut, washer, and clip are all Type 316 stainless steel, providing uniform, long-lasting corrosion resistance rather than surface-level protection.

Why This Product

• Built for cracked concrete without compromise - unlike basic expansion anchors, the Strong-Bolt 2 is specifically code listed and tested for cracked concrete, with secondary expansion capability that helps maintain structural load performance even after crack formation at the anchor point.
• Full seismic and high-wind approval across all design categories - qualification for seismic design categories A through F means this anchor can be specified for projects in virtually any geographic region without substitution, simplifying procurement and engineering coordination.
• All-316 stainless steel construction for harsh environments - with every component made from Type 316 stainless steel, this wedge anchor resists corrosion in wet, coastal, chemical-exposure, and other demanding service environments where carbon steel or plated anchors fall short.
• Installs with standard tools and common drill sizes - ANSI fractional sizing means no specialty drill bits or adapters are required, keeping installation straightforward and compatible with equipment already on site.

Specifications

• Model Number: STB2-37234S6F50
• Size: 3/8 in. x 2-3/4 in.
• Brand: Simpson Strong-Tie
• Anchor Type: Wedge-Type Expansion Anchor
• Diameter: 3/8 in.
• Length: 2-3/4 in.
• Thread Length: 1-5/16 in.
• Material: Type 316 Stainless Steel
• Finish: Type 316 Stainless Steel
• Component Material - Anchor Body: Type 316 Stainless Steel
• Component Material - Nut: Type 316 Stainless Steel
• Component Material - Washer: Type 316 Stainless Steel
• Component Material - Clip: Type 316 Stainless Steel
• Installation Drill Bit: 3/8 in.
• Wrench Size: 9/16 in.
• Testing Standards: ACI355.2 and AC193
• Packaging: Packs of 50 and Cartons of 200

Approved Applications

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

Frequently Asked Questions

What type of concrete applications is the Strong-Bolt 2 approved for?

The Strong-Bolt 2 is code listed for both cracked and uncracked concrete applications. It is also qualified for static and seismic loading conditions covering seismic design categories A through F, making it suitable for use in high-seismic and high-wind environments.

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

This anchor installs with a 3/8 in. drill bit and requires a 9/16 in. wrench size. Its standard (ANSI) fractional sizing ensures compatibility with common drill bits and tools.

Why is Type 316 stainless steel used for this anchor?

Type 316 stainless steel provides long-lasting corrosion resistance, making this anchor suitable for a wide variety of service environments where exposure to moisture or corrosive conditions is a concern. All components - including the anchor body, nut, washer, and clip - are made from Type 316 stainless steel.

What is the purpose of the dual undercutting embossments on the clip segments?

The dual undercutting embossments on each clip segment enable secondary expansion should a crack form and intersect the anchor location. This feature significantly increases the ability of the Strong-Bolt 2 to continue carrying load if the hole expands, enhancing performance in cracked concrete conditions.

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