What you should know about the new European standard on cold-formed welded hollow steel sections
Published: October 2020
After a prolonged delay, the third in the series of European standards on cold-formed welded hollow section structural steel has been published. This blog post explains where Part 3 sits within the series and how it differs from Part 1.
BS EN 10219-3:2020 Cold formed welded steel structural hollow sections - Part 3: Technical delivery conditions for high strength and weather resistant steels is a newly-published European standard that specifies the technical delivery conditions for high strength and weather resistant electric welded and submerged arc welded cold-formed hollow structural steel sections. It covers sections that are circular, square, rectangular or elliptical, and formed cold without subsequent heat treatment other than the heat treatment of the weld line.
This is the third in the three-part series of European standards dealing with cold formed welded hollow section structural steel. The series also includes BS EN 10219-1:2006 Cold formed welded steel structural hollow sections — Part 1: Technical delivery conditions and BS EN 10219-2:2019 Cold formed welded steel structural hollow sections — Part 2: Tolerances, dimensions and sectional properties.
The eagle-eyed will have noticed that Part 1 was last published in 2006; while Part 2 was revised in 2019. This is because BS EN 10219-1 was published in the Official Journal of the European Union (OJEU) under the Construction Products Regulation (CPR Regulation (EU) No. 305/2011), allowing the CE marking of all the products included in it.
However, when the relevant European technical committee (CEN/TC 459/SC 3 – “Structural steels other than reinforcements”) tried to revise BS EN 10219-1:2006 some issues arose. The committee wanted to extend the revised standard’s scope to include not only higher-strength steel grades and weather-resistant steels, but also other new processes such as quenched and tempered steels. Unfortunately, this meant that a revised Part 1 would then have difficulties complying with the CPR Regulation. As a result, the draft revision was never published as a standard.
As a work-around, the European technical committee then decided instead to incorporate the proposed additions to Part 1 into a new standard: BS EN 10219-3:2020, which is not under the Construction Products Regulation. This new standard is therefore voluntary and for use if the products it covers are to be used in mechanical engineering applications. It will not be possible to CE mark them under the CPR however.
To be specific, Part 1 covers six grades of non-alloy quality steels (S235JRH, S275J0H, S275J2H, S355J0H, SS355J2H and S355K2H) while Part 3 doesn’t include any. Meanwhile both Part 1 and Part 3 cover fine grain steels – feedstock condition N; but Part 3 only covers two grades, while Part 1 covers six.
However, when it comes to thermomechanical formed steels – feedstock condition M, Part 3 includes four more grades than Part 1. In terms of quenched and tempered steels – feedstock condition QT, Part 1 doesn’t include any, whereas Part 3 covers 24 grades; and for steels with improved atmospheric corrosion resistance, again, Part 1 doesn’t include any while the new Part 3 includes six separate grades.
This wider coverage of higher strength and more weather resistant steels means that those using Part 3 have the opportunity to better select the grade most appropriate to the steel section’s intended use and service conditions.
Finally, the grades and mechanical properties in the new standard are also generally comparable with Parts 3, 4, 5 and 6 in the BS EN 10025 series on hot rolled products of structural steels; and Parts 2 and 3 in the BS EN 10149 series on hot rolled flat products made of high yield strength steels for cold forming, making life easier for structural steel manufacturers, stockholders, distributors and testers.