Steel structures made from hollow sections often present a common challenge when installing supports, reinforcements and other auxiliary elements: how can you create a structural connection when there is no access to the inside of the section?
Traditionally, these applications have been solved using through-bolts or welding. However, both solutions have limitations when access is restricted or when faster installation is required.
To address this need, we have developed STRUTBOLT, an ETA-approved expansion anchor for hollow steel sections that enables structural fixings from just one side of the section, eliminating the need for welding or rear access.
The challenge of fixing into hollow sections
In many steel construction and industrial installation projects, structural members consist of closed sections that prevent access to the opposite side of the base material.
In these situations, through-bolts are no longer a practical solution, as they require a nut to be positioned and tightened from the opposite side. Welding, on the other hand, involves hot works, additional safety measures, qualified personnel and longer installation times.
Expansion anchoring systems therefore provide an alternative that simplifies installation while maintaining structural performance.
What is STRUTBOLT?
STRUTBOLT is an ETA-approved expansion anchor specifically designed for structural connections in hollow steel sections where access is only available from one side.
During installation, the system creates an internal expansion that provides a secure fixing inside the steel section, eliminating the need to access the inside of the profile.
This solution is suitable for:
- Steel-to-steel structural connections
- Fixing steel profiles to steel structures
- Installing non-structural components on steel structures
- Applications subjected to high loads
- Square, rectangular and circular hollow sections
Designed to solve real on-site challenges
According to our technical team, STRUTBOLT was developed after identifying numerous applications where existing solutions did not match real installation conditions.
The objective was to create a system that allows installers to work from just one side of the section while maintaining structural performance and reducing on-site complexity.
This reflects a growing industry trend towards solutions that reduce dependence on complex processes while enabling faster, safer and more predictable installation.
Advantages over traditional solutions
No welding required
STRUTBOLT enables structural connections without hot works, reducing welding-related risks and installation time.
Installation from one side only
Unlike through-bolts, no access to the rear side of the section is required, making installation in closed hollow sections much easier.
ETA approved for structural applications
The system is ETA approved for structural applications, providing engineers and installers with technical assurance and confidence.
Greater on-site efficiency
Fewer installation steps simplify project planning, reduce installation time and improve overall productivity.
Quick and simple installation
- Pre-drill the components to be fixed.
- Insert the anchor into the hollow section.
- Hold the outer sleeve with an open-end wrench.
- Tighten the bolt to activate the internal expansion and complete the fixing.
The entire installation can be completed from one side of the section, with no rear access or additional operations required.
Want to learn more? Discover the complete STRUTBOLT range.