In construction, small details can make the biggest difference. A simple-looking connection — a bolt into a hollow steel section — can be deceptive; when structural integrity is at stake, appearances mislead.

Several products now resemble the Hollo-Bolt®, but similarity ends at the surface. Unauthorised copies typically fall short on strength, fatigue resistance and safety margins. The consequences can include elevated risk of failure, higher whole-life costs and increased liability.

That’s why engineers, contractors and asset owners should understand the difference between the original Hollo-Bolt, invented by Lindapter in 1995, and look-alike fasteners that cannot match its performance or approvals.

Hollo-Bolt®: the first expansion bolt for structural steel
Launched in 1995, the Hollo-Bolt® enabled fast, safe, approved connections to structural hollow sections (SHS) without welding or on-site drilling. The principle is simple: insert the bolt into a pre-drilled hole; tightening draws an internal cone to expand the sleeve against the inner wall; the result is a secure, high-strength bearing connection that distributes load and resists slip, vibration and fatigue. It opened new design possibilities and made builds quicker, safer and more economical.

Genuine Lindapter Hollo-Bolts — engineered and certified
Every genuine Hollo-Bolt is designed and tested for lasting performance and traceability.

1. Easy identification
   Each unit is stamped “Lindapter” with size (e.g., M8HB) on the collar for instant authentication.

2. Independent approvals
   Only Lindapter Hollo-Bolts carry comprehensive third-party certifications such as ETA, CE Marking and ICC-ES, verifying load capacity, safety and real-world performance for structural use worldwide.

3. Distinctive collar
   Two flat, parallel sides on the collar aid alignment and act as a quick visual cue on site.

4. High Clamping Force (HCF)
   Exclusive to M16 and M20, HCF Hollo-Bolts deliver up to three times the clamping force of standard designs, cutting displacement and boosting resistance to vibration and dynamic loads.

Why risk imitations?
Unapproved copies lack rigorous testing, traceability and documented performance. Small deviations in design or material can reduce capacity, increase movement or fail under dynamic conditions. With Lindapter you’re investing in verified safety, compliance and reputation.

Advantages over traditional methods
No hot works: Removes welding on site, along with permits, fire watch and associated costs.
Time saving: Fits with standard hand tools; no need to drill through both walls or weld in awkward locations.
Cost efficiency: Faster installation reduces labour, disruption and shutdown costs — critical in rail, offshore and industrial settings.

Performance versus alternatives
Through-bolting needs access to both sides and can spoil aesthetics. Hollo-Bolts give a clean, flush finish and are tested and certified for demanding environments — unlike cheap copies.

Design flexibility: head types and finishes
Hexagonal head for heavy-duty applications; countersunk where clearance or detailing matters; Flush Fit for concealed connections. Finishes include zinc plated, hot-dip galvanised, Sheraplex and stainless steel to suit everything from interiors to aggressive offshore conditions.

Installation and removal
Drill a single hole in one wall of the section, insert the Hollo-Bolt and tighten with a standard wrench or impact driver; the mechanism expands to lock in place. To remove, reverse the process — no permanent damage, enabling future modifications.

Selected applications
Military History Museum (Germany): extensive perforated steel cladding.
Wilshire Grand Center (California, USA): curved skylight atrium structure.
ITER nuclear fusion upgrade (France): SHS beams and pipe supports.
These projects demonstrate certified strength, speed of install and life-cycle savings.

Choose the original — choose safety
Hollo-Bolt remains the benchmark for hollow-section connections, backed by three decades of proven use, comprehensive approvals and worldwide trust. Look-alikes may mimic the shape; they cannot replicate the testing, certifications or confidence of Lindapter engineering. When structural performance and safety are on the line, specify the original Hollo-Bolt.