When Standard Galvanised Steel Tube Stops Being Enough
Most corrosion protection does a reasonable job in reasonable conditions. The moment your application moves into genuinely hostile territory, whether that is an ammonia-saturated livestock unit, a coastal installation battered by salt air, an exposed lineside structure, or the relentless humidity inside a commercial growing tunnel, "reasonable" stops being adequate. Zinc flakes. Rust creeps in. The replacement cycle begins before it should.
MAGNAtube® is our answer to that problem. It is our flagship ERW tube product, manufactured from a double-sided zinc, aluminium, and magnesium-coated coil, with our proprietary MAGNAfusion® weld repair process delivering 100% corrosion protection across both the interior and exterior of every length. The result is a galvanised steel tube that does not merely coat the surface. It becomes part of the steel.
In exhaustive tests conducted by leading UK test house Rotech Laboratories, MAGNAtube® lasted the equivalent of 100 years without significant deterioration. That is not a marketing estimate. It is a verified result from an independent laboratory, and it is the foundation on which every MAGNAtube® specification is built.
Why Choose Top Tubes as Your ERW Tube Supplier?
ISO 9001 Certified Production
Working to ISO 9001 standards, we monitor weld integrity, dimensions and finish at every stage of production.
ERW Tube Manufacturing
Specialists in electric resistance welded tube, delivering consistent strength, accuracy and repeatable performance.
Flexible Production Volumes
From development runs to scheduled high-volume orders, we plan capacity around your demand.
Full Material Traceability
Every tube is traceable from steel coil to dispatch, supporting regulated and audited supply chains.
All Core Processes
Under One Roof
Managing these operations internally reduces handling, limits delays and keeps accountability clear. There are fewer handovers and fewer variables.
We often describe ourselves as “easy to buy off.” That is deliberate. Industrial supply should be straightforward.
Did You Know?
At Top Tubes, if a single weld seam fails during testing, we stop the batch immediately and reset production parameters before restarting. This disciplined approach protects weld integrity and ensures that every ERW tube leaving our facility meets our internal standards, not just minimum requirements.
| Round | 19mm OD up to 76.20mm OD |
| Square | 16mm x 16mm up to 60mm x 60mm |
| Rectangle | 25mm x 15mm up to 80mm x 40mm |
| Flat Sided Oval | 25mm x 12mm up to 80mm x 40mm |
| Special Section | As required |
Did you know?
As a complete tubes and pipes manufacturing company, we support structural, architectural, automotive and specialist requirements.
Whether you require a steel tubing manufacturer for ongoing supply or a manufacturer of steel pipe for a defined project, our team can advise on the most suitable option.
What Separates MAGNAtube® ?
The difference begins at the coil. MAGNAtube® is manufactured from a premium double-sided zinc, aluminium, and magnesium (ZAM) coated coil. This is a fundamentally more advanced coating chemistry than the pure zinc layer found on standard galvanised steel tube, and each element in the ZAM system plays a specific, active role in long-term protection.
Zinc provides the sacrificial base layer, corroding preferentially to protect the steel beneath. Aluminium forms a dense oxide barrier that slows the rate of attack at the surface. Magnesium actively suppresses corrosion at cut edges and any area where the coating has been disrupted, generating protective compounds in the presence of moisture. Together, the three deliver a self-healing protection system capable of up to 20 times the corrosion resistance of standard galvanised tube. MAGNAfusion® takes that further still.
| Performance Metric | MAGNAtube® Result |
| Corrosion resistance vs galvanised tube | Up to 20 times greater |
| Independent service life test | 100 years without significant deterioration (Rotech Laboratories, UK) |
| Weld seam protection | 100% interior and exterior via MAGNAfusion® |
| Coating chemistry | Double-sided zinc, aluminium, and magnesium (ZAM) |
| Self-healing capability | Active at cut edges and damaged zones |
| Scratch resistance | Superior to standard galvanised tube |
| Manufactured by | Top Tubes Ltd, Wednesbury, West Midlands |
MAGNAfusion®: 100% Weld Seam Protection, Inside and Out
Every ERW tube has a weld seam. In a standard galvanised steel tube, that seam represents the weakest point in the corrosion protection system. The zinc coating is disrupted during the welding process, and the weld zone is left either partially protected or reliant on a basic zinc spray repair that does not match the integrity of the parent material.
MAGNAfusion® is our proprietary weld repair process, developed specifically to restore the full ZAM coating to the weld zone to a standard equivalent to the surrounding tube surface. The result is a tube with complete corrosion protection across the exterior and the interior, with no compromised seam, no untreated zone, and no weak point in the protection system. It is the technical detail that separates MAGNAtube® from every other galvanised steel tube on the market, and it is the reason our customers in agriculture, coastal construction, and rail infrastructure keep specifying it, project after project, year after year.
Self-Healing Protection and What It Means for You
With a standard galvanised steel tube, cutting, drilling, or forming after galvanising exposes bare steel at every cut face. In high-moisture or chemically aggressive environments, rust can begin within weeks. On a production line, this creates a secondary process requirement: every cut edge must be treated before dispatch. That step takes time, introduces a quality variable, and adds cost.
MAGNAtube® removes it. Because the ZAM coating chemistry actively generates protective compounds at disrupted areas, our customers can cut, drill, and process MAGNAtube® without requiring additional edge treatment before the product leaves their facility. The tube manages it.
For manufacturers and fabricators, this is not a minor convenience. It eliminates a process step, reduces production time, and removes a source of quality risk in a single specification decision. One of our long-standing customers in the agricultural structures sector stores MAGNAtube® outside prior to manufacture and dispatch, with no signs of degradation. That is what 30 years of consistent performance looks like in practice.
Fun Fact:
We are the only manufacturing company with such vast capabilities in the Midlands. We boast a 14,000-square-meter factory in the heart of the UK. We take pride in having full control over the tube manufacturing process. From coil slitting to ERW tube manufacturing and tube laser cutting, we have complete control over every step. Additionally, we ensure full traceability of materials. There is no one else like us!
Where MAGNAtube® Galvanised Steel Tube Performs Best
MAGNAtube® was developed specifically for environments where standard galvanised steel tubes cannot keep pace. It performs reliably in conditions that accelerate corrosion in conventional products, making it the correct specification choice in any application where longevity, reduced maintenance, and structural integrity matter more than the lowest upfront cost.
Agriculture and Livestock
Ammonia-rich air inside livestock housing attacks standard galvanised steel tubes faster than almost any other environment. MAGNAtube® is specifically engineered to resist alkaline and ammonia-rich conditions, making it the preferred tube specification for penning systems, feed line infrastructure, dairy housing frameworks, and commercial growing structures across the UK and Europe. We have customers in the agricultural sector who have trusted MAGNAtube® for over 30 years, with the product continuing to perform in the same structures where it was first installed.
Coastal and Marine
Salt-laden air and high winds accelerate corrosion at a rate that strips standard galvanised steel tube well within a typical structure's intended service window. MAGNAtube® provides a service life comparable to aluminium and stainless steel in coastal conditions, at a significantly lower cost. It is a proven, practical specification for coastal structures, maritime installations, and any exposed outdoor infrastructure where a conventional galvanised tube would require premature replacement.
Commercial Greenhouses
The temperature variation, sustained humidity, and chemical exposure inside commercial growing environments are severe. MAGNAtube® has been trusted by greenhouse structure manufacturers for over 30 years. Its strength and corrosion resistance enable wider spans and taller configurations with reduced internal support, giving growers better air circulation and more productive usable space within the same footprint.
Defence
Defence contractors and MOD-aligned projects require a tube that maintains its integrity under abrasion, climate extremes, and operational stress. MAGNAtube®'s toughness, scratch resistance, and proven long-term corrosion performance make it a consistent choice for deployable shelters, containment systems, and high-security structural applications where product failure is not an acceptable outcome.
Rail and Lineside Infrastructure
Reduced maintenance intervals and long service life in varying climatic conditions are the defining requirements in rail and overhead electrification applications. MAGNAtube® delivers both. Its durability and abrasion resistance under demanding operational conditions make it an established choice for lineside structures, overhead electrification support systems, and rail-adjacent infrastructure where access for maintenance is limited, and reliability is non-negotiable.
Renewable Energy
Solar farms and wind installations are frequently sited in exposed, coastal, or semi-industrial environments where long-term corrosion management is a structural concern from day one. MAGNAtube®'s resistance across the full spectrum of environmental attack makes it a strong specification choice for mounting structures, support frames, and infrastructure components throughout the renewable energy sector.
Dont See Your Industry?
If your sector is not listed, speak to us. As a long-established steel tube supplier, we are accustomed to supporting specialist and niche applications.
Quality Controls That Do Not Compromise
Every length of MAGNAtube® leaves our 14,000 square metre facility in Wednesbury, West Midlands, against a quality framework with no tolerance for deviation. Our ERW tube manufacturing process operates under a BS EN ISO 9001:2015 certified quality management system, UKAS accredited, and every tube carries full material traceability from raw steel coil to finished product.
Our quality control position is straightforward: if a single seam cracks during a tube test, the entire batch is discarded, restarted, and the tolerances are reviewed. There is no exception process. We either produce a tube that meets the specification, or we do not ship it.
Structural tube is manufactured to EN 10219-1:2006 and EN 10219-2:2019, the cold-formed welded structural hollow section standards that give design engineers the compliance assurance they need. Testing on every production run covers tensile strength, elongation, and yield; flattening for ductility and weld integrity; expansion behaviour; and non-destructive weld testing via ultrasonic or X-ray inspection. Visual inspection is the final check before dispatch.
Did you know?
If you choose to handle all your tube processes in-house, you could save a fortune. Just ask a member of our team, "How will Top Tubes' In-House Services Save Me Money?" Contact Us Today!
All Core Processes
Under One Roof
Quality Control in Our Steel Tube Manufacturing
Quality control is central to how we operate.
We carry out:
Tensile Testing
Our contact-free cutting eliminates deformation and ensures repeatable, tight-tolerance results.
Flattening tests
With CAD/CAM integration, we go from design to cut with minimal delay.
Impact testing
Our energy-efficient machines and material-saving practices reduce waste and emissions.
Expansion testing
Our energy-efficient machines and material-saving practices reduce waste and emissions.
Non-destructive weld testing
Our energy-efficient machines and material-saving practices reduce waste and emissions.
Visual inspection
Our energy-efficient machines and material-saving practices reduce waste and emissions.
Did you know?
If a seam fails during testing, we do not release the batch.
We reset tolerances, review parameters and restart production where necessary.
That discipline protects both our standards and your supply chain.
One Facility. Every Process. No Handoffs.
MAGNAtube® is only available from us. We developed it, we manufacture it, and we stand behind every length that carries the name. As the UK's only steel tube producer with the full production cycle under one roof, from coil slitting through ERW tube milling to laser cutting and dispatch on our own transport fleet, we give you a supply chain with a single point of accountability and no third-party handling between our mill and your door.
Our production capacity exceeds 50,000 tonnes per annum across two modern ERW mills, with the flexibility to handle everything from small prototype runs to large-volume repeat contracts at the same level of service. Our just-in-time stockholding capability means you draw on agreed stock precisely when your production schedule demands it, without carrying unnecessary inventory.
We have been manufacturing ERW tubes since 1994. In that time, we have built a reputation not on complexity, but on being straightforward to work with. We know our product, we treat buyers as intelligent professionals, and we make the procurement conversation as efficient as the tube itself.
If your current galvanised steel tube supplier is creating problems rather than solving them, it is time to have a different conversation.
Get in touch
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