Precision in Practice: The Importance of Anchor Edge Distance in Steel-to-Concrete Connections

In the world of structural connections, every millimeter counts—especially when it comes to anchor edge distance. This simple but vital detail can determine whether a steel-to-concrete connection performs flawlessly or fails under pressure.

At SHARCON, we take anchor edge distance seriously. Because when anchors are installed too close to the edge of concrete, you don’t just risk a minor error—you risk cracking, breakout, or even structural failure. Here’s why it matters, how it’s determined, and what we do to make sure it’s always right.

What Is Anchor Edge Distance?

Anchor edge distance is the distance from the center of an anchor bolt to the nearest edge of the concrete element—typically a slab, wall, or footing. This spacing ensures the concrete surrounding the anchor can handle the applied forces without cracking, splitting, or breaking out.

If anchors are placed too close to an edge, the result can be a concrete breakout cone—a wedge-shaped failure where part of the concrete is pulled out along with the anchor. This weakens the structure, undermines safety, and can lead to costly repairs.

How Is the Required Edge Distance Determined?

There’s no one-size-fits-all. Several variables impact how far from the edge an anchor must be placed:

• Anchor bolt diameter: Larger bolts require more distance.

• Concrete strength: Stronger concrete can handle shorter distances—but only within engineering limits.

• Embedment depth: Deeper anchors distribute forces more effectively, but edge distance still applies.

• Type of load: Tension, shear, or combined loading conditions influence required spacing.

• Spacing between bolts: Anchor groups must be laid out with proper spacing to avoid overlapping stress zones.

  
  

These are all evaluated by engineers during design, but detailers must double-check them before fabrication.

Risks of Inadequate Edge Distance:

Cutting corners on edge distance can result in:

• Concrete cracking during installation

• Reduced anchor capacity and early failure

• Failed inspections or code violations

• Time-consuming rework and costly delays

  
  

Real-life failures caused by improper anchor placement have led to significant structural issues—and even collapse in extreme cases.

How SHARCON Gets It Right

We don’t leave edge distance to chance. Here’s how our team ensures anchors are properly placed every time:

1. 3D Modeling in Tekla Structures

We model anchor bolts in full 3D, relative to the concrete geometry, to catch potential edge or embedment conflicts early.

2. Clash Detection and Rules-Based Checking

Our tools highlight edge distance violations before drawings go out. These checks include bolt-to-edge gaps, group spacing, and tolerance zones.

3. Collaboration with Engineers

When potential issues arise, our detailers work with structural engineers to reconfigure bolt layouts, adjust base plate dimensions, or propose alternate solutions.

4. Manufacturer Guidelines

We reference anchor bolt manufacturer data to ensure our detailing complies with technical requirements—including edge and spacing tolerances.

Final Thoughts: Small Detail, Big Impact

Anchor edge distance may seem like a small parameter on a drawing, but in reality, it’s one of the most important factors in structural safety.

At SHARCON, we detail with performance and safety in mind—from the ground up. If your project involves anchor bolts in concrete, let us help you get the detailing right the first time.

Because in construction, precision isn’t just about speed—it’s about security, compliance, and peace of mind.

📞 Call us: +61 478 727 338

📧 Email us: shyam@sharcon.com.au

🌐 Visit our website: www.sharcon.com.au