Quick Search

761 Major UK steel manufacturer talks about steel substitution

Report ID: 761

Published: Newsletter No 53 - January 2019

Report Overview

A correspondent is concerned that cold formed S235 steel is being used in place of hot formed S355 steel, as this can have dangerous implications.

Report Content

A correspondent has written in response to the issues that have arisen from CROSS report 740 Common use of S235 cold rolled steel instead of S355 hot rolled steel. As a UK manufacturer of both hot and cold structural hollow sections, they are concerned that cold formed S235 steel is being used in place of hot formed S355 steel, as this can have dangerous implications.

In their view, there is good availability of both cold and hot formed steel in the UK and they feel that a few may be letting the industry down. They refer to the Hot v. cold formed hollow sections article published in The Structural Engineer in 2007 on the comparison and effects of hot and cold structural hollow sections and ask if this article should be re-issued with the addition of CE marking to help the industry?

The correspondent notes that S235 is generally manufactured for the commodity industry and therefore does not require the same quality, traceability and testing as S355, so will have a price difference. The two product standards, EN10219 Cold formed Structural Hollow Sections and EN10210 Hot finished Structural Hollow Sections, are different.

The correspondent has come across the substitution of S235 for S355 but is very alarmed that this is happening with cold S235 for hot finished S355. Material manufactured to EN10219 and EN10210 will be CE marked, and there should be a clear identification with the certificate and label that goes with the steel.

The correspondent goes to say that if there are any issues arising from the mis-use or mis-selling, then the responsibility lies with the person/company placing the product in the market place.

The main problem, they believe, is that the tested values of the cold EN10219 will be much higher than the minimum yield certified due to the manufacturing process but will lose yield when heat is applied. The people responsible for up-grading are playing a dangerous game.

Comments

A key safety message that CROSS comments keep repeating is that there should be verification that what is built matches design intent.

There can be no more serious deficiency than having a material that doesn’t have the strength the designer thought it had. A rather obvious issue is that you can’t tell the difference in strength between two pieces of steel (or concrete) just by looking at the product. Therefore, QA on product procurement (and QC) are essential components in assuring design safety.

There are issues around the whole construction industry regarding substitution of materials (usually for something cheaper), the clear marking of products and the availability and ability of someone to check. If components and materials are marked clearly (and accurately), and there is rigorous checking on site then these things can be avoided.

The matter of false certificates has previously been addressed by SCOSS in the Alert Anomalous documentation for proprietary products - February 2013.

 

CROSS depends on you for reports - if you have experienced a safety issue that you can share with CROSS, please Submit a CROSS Report which is treated as confidential

If you have any comments regarding this CROSS report, please Submit Feedback

View other CROSS reports published in Newsletter No. 53


Email Updates

How to Report

Online submission:
Submit by post: