Correction:
In the story below RNZ reported that steel bars purchased from Steel & Tube for use on its transmission masts near Taupo were below required strength. Steel & Tube has challenged the story on several points.
RNZ accepts the company’s statement that the material was threaded rods, not steel bars. It also now accepts that the test certificates were not related to the rods RNZ actually purchased.
We also accept Steel & Tube’s statement that the threaded rods RNZ purchased were compliant to the specification (grade 4.6) requested by and supplied to RNZ.
A trickle of complaints about overseas steel manufacturers faking strength certificates, sometimes blatantly, is turning into a flood.
The RNZ radio antenna near Taupo. If the steel bars failed, the five masts they help support would fall. Photo: RNZ
That has prompted the trans-Tasman watchdog of steel testing to call on the government to follow Europe's stringent regime, under which chief executives must sign that steel is up to standard or face a potential jail term.
One example of the weak New Zealand regime is very close to home - steel bars supplied to RNZ to anchor its 65-metre high radio antenna near Taupo.
The bars came from China, imported by Steel & Tube, but had only 80 percent of the strength shown on their test certificates - also from China.
Steel & Tube declined to be interviewed. It said it took product compliance and RNZ's assertions very seriously, and had sought clarification of anomalies in the data.
It said when that information was forthcoming, it would be in a position to respond.
Australasian Certification Authority for Reinforcing and Structural Steels (ACRS) audits and certifies local and foreign steel plants in 15 countries so they could guarantee its products complied with New Zealand standards.
ACRS New Zealand head Stephen Hicks had first-hand experience of the UK regime, and said it was the "wild west" in New Zealand.
While both New Zealand's steel manufacturers held ACRS certificates, steel distributors - firms like Steel & Tube and Fletchers - did not, although they could.
Dr Hicks speculated they might not want to give an independent authority the power to shut them down if their testing did not make the grade.
It was entirely coincidental the weak bars were found when Steel & Tube was involved in two Commerce Commission investigations.
Steel mesh from several companies including Steel & Tube is being strength tested as part of a Commerce Commission investigation. Photo: Cultura Creative
An engineering team working on the RNZ antenna had samples tested locally by lab SGS.
They showed a strength of 460 Megapascals. But the Chinese certificates from Zhejiang Junyue company in Haiyan said the bars averaged 577 MPA.
Steel & Tube said there were inconsistencies in the information and samples, and it needed to know more before commenting.
It had made clear to RNZ when the bars were ordered that the tests would be done in China.
Dr Hicks said steel buyers were more often coming to ACRS worried about certificates.
"[It has] been a trickle but I think it's started to become a bit more like a flood these days," he said.
"For instance, we maybe would have three different certificates all having the same value and signed off by the same person, which is very unusual ... It's so blimmin' obvious you are surprised they would even attempt it."
But ACRS could only warn buyers.
Whether steel ended up in a building or road was up to the buyer - and the engineers, who had to sign off on a building and were liable, were the only ones preventing poor steel from being used, he said.
For its part, ACRS had 150 licence holders in 15 countries, who were audited each year to ensure their products complied with New Zealand and Australian standards.
He said the gold-plate standard in steel quality was Europe and the UK, where no steel could be used structurally unless it was certified, and all testing had to be audited by a third party.
In the face of a resistant Ministry of Business, Innovation and Employment (MBIE), he said unfortunately it came back to political will.
"How it would look would be that the government mandates the performance requirements in the product standards, saying these tests have to be repeated three or four times, and those tests have to be done or overseen by a third party organisation."
He said the other crucial catalyst would be customer demand - and the government was key there too because it could require all road builders to use only properly certified steel.
'Steel cheaper than cabbages'
Building Industry Federation chief executive Bruce Kohn said reports of sub-standard steel had been a wake-up call for the industry.
While Mr Kohn did not believe problems with poor steel products were systemic, he warned the sector needed to understand the impact of the over-supply of steel globally.
"All suppliers and buyers need to be aware there can be variations in steel quality from Asia. In China there's currently a saying that 'steel is cheaper than cabbages'."
The Heavy Engineering Research Association deals with steel construction in buildings.
Director Wolfgang Scholz said while it tried to lead the way by having a traceable supply of steel certified products, there were clearly problems with some non-compliant products on the market.
Dr Scholz said MBIE needed to take a firmer line to ensure standards were met.
"We request MBIE to really take the lead there and make sure we have got the policing element in place. This is not the case, it very much relies on voluntary contributions."
Dr Scholz said engineers had to sign-off steel products and then take responsibility for how they performed.