Why ACRS Certification and the MTC Are Both Required — Not One or the Other

There’s a version of this conversation that happens regularly on Australian construction projects. A shipment of structural hollow sections arrives on site. The documentation includes mill test certificates — proper ones, with heat numbers, chemical analysis, mechanical test results, the lot. The procurement manager asks for the ACRS certificate. The supplier says the product is certified to AS/NZS 1163, points to the MTC as evidence, and asks why a separate certificate is needed.

The answer to that question — and why the ACRS certificate is required even when the MTC looks complete — gets to the heart of how steel product quality assurance actually works on regulated Australian construction projects.

What Each Document Proves

The mill test certificate (MTC) is a record of what happened with a specific batch of steel. It shows the chemical composition of the melt, the mechanical test results from samples taken during production, the heat number, and the dimensional checks. A well-prepared MTC tells you that the material in this shipment, from this heat, met the specified requirements when it was tested.

What the MTC cannot tell you is whether the testing was done correctly, whether the sampling was representative, or whether the mill’s quality system is functioning consistently. The MTC is self-reported by the manufacturer. It’s a test result, not an audit.

The ACRS certificate (Australasian Certification Authority for Reinforcing and Structural Steels) is an independent third-party verification that the manufacturer’s production and quality system has been assessed and found to comply with the relevant standard — in this case, AS/NZS 1163 for cold-formed structural steel hollow sections. ACRS conducts periodic audits of certified mills, including unannounced testing of product samples taken from the market. A valid ACRS certificate on a product means an independent body has verified that the mill’s process and quality system actually produce compliant product, not just that the mill’s own documentation says so.

Together, the two documents address different parts of the quality question: the ACRS certificate says the mill is capable of producing compliant product and has been independently verified to do so; the MTC says this specific batch was tested and met the requirements.

Why Projects Require Both

Australian and New Zealand building codes reference AS/NZS 1163 for structural hollow sections used in building and infrastructure. The National Construction Code and various state-level requirements increasingly specify that structural steel must be sourced from ACRS-certified mills, particularly for Class 2 and higher buildings and for applications where the steel is part of the primary structural system.

This isn’t bureaucratic formalism. The practical backstory is that non-compliant structural steel has appeared in Australian supply chains — material marked or documented as meeting local standards but actually produced to different specifications with lower yield strength, higher carbon content, or inadequate impact performance. MTC-only verification doesn’t reliably catch this, because MTCs from unaudited sources can be incomplete, incorrect, or in some cases fabricated.

ACRS certification closes this gap. A mill that can’t sustain independent audit won’t hold ACRS certification. Requiring ACRS-certified product filters out suppliers whose quality systems haven’t been externally verified, regardless of what their MTCs say.

How to Verify an ACRS Certificate

An ACRS certificate is straightforward to verify. The ACRS website (acrs.org.au) maintains a public register of current certifications by company and product. For any ACRS certificate presented with a delivery, you can check:

• Whether the company holding the certificate matches the actual manufacturer (not a distributor or trader claiming the manufacturer’s certification)
• Whether the certificate covers the specific product — the standard, grade, and section type — that you ordered
• Whether the certificate is current (ACRS certifications have expiry dates and are maintained through ongoing audits)
• The scope of the certification, including which manufacturing locations are covered

A common point of confusion is that an ACRS certificate held by a steel distributor is not the same as a manufacturer’s certificate. If a distributor holds an ACRS certificate, check what that certificate actually covers — it may cover the distributor’s own processing operations or traceability systems, not the manufacturer’s production of the base steel.

Reading the MTC Alongside the ACRS Certificate

Once the ACRS certificate is confirmed as valid and in scope, the MTC verification becomes more reliable because you’re now checking a document from a source whose quality system has been independently audited.

For AS/NZS 1163 C350 or C350L0 hollow sections, the MTC should confirm:

Yield strength — minimum 350 MPa for the relevant section size and wall thickness, noting that the standard tables should be consulted because requirements can vary with dimensions.

Tensile strength — minimum 430 MPa.

Elongation — minimum values per the standard, which vary by grade and section type.

Impact testing — required for L0 grades only. If L0 is specified, the MTC must include Charpy impact test results at 0°C. If the MTC shows no impact test results and the order was for C350L0, the delivery doesn’t meet specification.

Carbon equivalent — particularly relevant if the sections will be welded on site. Higher carbon equivalents require more stringent preheat procedures.

Heat number traceability — confirm that the heat numbers on the MTC correspond to markings on the actual sections. For hollow sections, markings are typically on a label or stencilled on the surface.

What Happens If the ACRS Certificate Is Missing

On projects that contractually require ACRS-certified product, accepting delivery without a valid ACRS certificate creates a documentation gap that’s difficult to close after the fact. The options are limited: return the material and reorder from a certified source, seek a project-specific concession from the structural engineer and certifier (which adds time and may not be granted), or accept the risk of a non-conformance finding during construction audit.

None of these outcomes is appealing, and none is as straightforward to fix as confirming the certification before the order is placed. The ACRS register is publicly accessible, the check takes a few minutes, and it should be part of the supplier qualification step on any project where ACRS-certified product is specified.

The combination of a valid ACRS certificate and a conforming MTC is the minimum documentation that gives a project team confidence that the structural steel in the building is what it’s specified to be. Either one alone leaves a gap.