An issue has arisen in the market where steel is being sold as one grade and then upgraded to higher grades after purchase. This practice significantly increases the risk to building safety and resiliency. Consequently, compliance managers and certifiers need to be aware of these risks.

ACRS has become aware of some end-users purchasing lower grade steel, having some key material properties tested at a laboratory, and then upgrading the product based on this limited testing. We have also seen occurrences of end-users upgrading product to a higher strength grade based on test certificates. Common examples are purchasing a 350 grade and then, based on a third-party impact test, upgrading it to 350L0; or upgrading a 350 grade to a 400/450 grade after reviewing test certificates. 

Requirements of the standards

In all the structural steel standards that ACRS certifies to – AS/NZS 1163, AS/NZS 3679.1, AS/NZS 3679.2 and AS/NZS 3678 – it is clearly stated that the steelmaker’s test certificate designation is the actual designation of the product. 

The standards (AS/NZS 3678:2016; AS/NZS 1163; AS/NZS 3679.1; and AS/NZS 3679.2 via reference to AS/NZS 3678) state that product must identify its grade of steel (11.1c “Identification, Test and Inspection Certificates”). The standard further states that a test certificate shall be available to the purchaser for all products manufactured to this standard, for each batch produced (11.2.1). And that an intermediary shall only pass on either an original or a copy provided by the manufacturer without any alteration (11.2.2). An intermediary here means a supplier, and not a manufacturer. 

Products not marked with the provisions specified in this clause are non-compliant with this standard (11.1). So, any third-party testing used to specify a different grade would not be considered valid.

Compliant and non-compliant testing

When assessing and certifying steel manufacturers, ACRS ensures that they have the required systems/processes; testing; test pieces selection; product identification; and test certificates to fully meet the requirements of the standard for the grade and size/shape of product. We review each grade individually as each grade has its own unique requirements. 

The standards state that test samples for tensile, impact, and through-thickness tensile tests shall be taken as laid out in Clause 9.2 “Position and Orientation of Test Pieces” (9.1 “Selection of Test Samples”) and that test pieces shall be representative of the body of the product. Each standard stipulates the position and orientation of the test piece: sampling incorrectly can lead to incorrect test results. 

If additional testing is undertaken, you can’t be sure that the test piece is representative of the body of the product, or that the test piece/s selected have been taken in the correct position and prepared correctly.

Additionally, in the determination of steel grades, manufacturers are required to assess material properties over a period of time to determine the variation and ensure the product fits within the required statistical deviations. A single test is only representative of the sample at the time taken and may not represent all the product delivered. ACRS would recommend that end users rely on the test results as provided by the manufacturer, as they have the knowledge and expertise to indicate that a material is compliant to the standard.

ACRS certification withheld

ACRS is frequently asked to review product test certificates, or random test piece results, to validate the end use of specific products. ACRS will not do so, because test certificates or results are only one part of the applicable standard. ACRS issues certification only when a steel mill fully meets all requirements of that standard – not for random sampling.

If a quality issue arises because of additional testing, or because a product claims a higher grade based on a test certificate’s mechanical properties, then the steel manufacturer will refer the complainant back to the test certificate which clearly states the original grade that the product was manufactured to and thus the intended end use. Selecting a base grade and then undertaking additional testing at another laboratory or upgrading based on test certificates invalidates ACRS certification.

ACRS does allow mills to dual certify product where that mill clearly has all the systems in place. The product is marked as such and the test certificates state all the relevant grades. Those mills have unique processes and procedures to achieve dual certification, as verified by ACRS assessment and listed on the applicable certificate.