Is there a code for hollow steel sections?

Yes. AS/NZS 1163:2016 is a key product standard for cold-formed, electric resistance-welded structural hollow sections in Australia and New Zealand. It covers circular hollow sections (CHS), among other shapes, and specifies production and supply requirements. Its use on a particular project follows the applicable contract, design and construction requirements; product conformity alone does not establish structural design compliance.

Code for Hollow Steel Sections: What Is AS/NZS 1163?

AS/NZS 1163:2016 specifies requirements for the production and supply of cold-formed, electric resistance-welded structural hollow sections. For a CHS order, the specified grade, dimensions, testing and documentation should be checked against the project requirements. Product conformity alone does not establish the adequacy of a structural design.

Steel Grades and Mechanical Properties Defined by the Standard

The standard divides hollow sections into different grade names. Each grade has a minimum yield strength given in MPa, and the “L0” suffix means that the Charpy V-Notch impact resistance at 0°C (≥27 J) has been confirmed. This is very important for structures that are exposed to low temperatures or dynamic loading. These grades are on offer:

• C250 / C250L0 — A nominal 250 MPa strength category; confirm the selected grade and impact requirements in the project specification.
• C350 / C350L0 — A nominal 350 MPa strength category; selection depends on the required dimensions, impact properties and design checks.
• C450 / C450L0 — A higher nominal strength category that may be selected where the design calls for it; member stability and connection capacity must also be checked.
• C550L0 — A higher-strength impact-designated grade; availability and suitability should be verified for the ordered size and structural design.

Weldability depends on the actual chemical composition, section thickness, restraint and fabrication procedure. A fabricator should review the supplied chemical analysis and qualify or select a suitable welding procedure under the applicable fabrication standard.

These grade names can’t be switched with ASTM A500 or EN 10219 grades without an engineering review. This is because the minimum yield strength, maximum elongation, and impact test requirements are different for each framework.

Technical Standards and Testing Methods for Structural Steel Hollow Sections

Quality assurance for AS/NZS 1163 hollow sections is based on a set of organized tests that look at both the purity of the material and the conformance of the dimensions. The following checks must be done and recorded by procurement teams that buy from foreign manufacturers.

The checks and records required for an order depend on the specified grade, product standard and purchase conditions. Purchasers should confirm the applicable inspection and acceptance criteria before production:

• Tensile Testing (per AS 1391) — This checks that the minimums for yield strength, ultimate tensile strength (UTS), and extension at fracture have been met. In the case of the C350 CHS, the UTS must be at least 430 MPa.
• Charpy V-Notch Impact Test — Needed for all grades that are labeled as L0, and items tested at 0°C must absorb at least 27 J to pass. For structures in southern Australia or high-altitude New Zealand, this test has to be done.
• Non-Destructive Testing (NDT) — Eddy current or ultrasound testing along the lengthwise weld seam can find flaws in the weld that can’t be seen with the naked eye.
• Dimensional Verification — Check outside diameter, wall thickness, length and straightness against the applicable AS/NZS 1163 requirements and the dimensions stated in the order. Record actual measurements with calibrated equipment.

A mill test certificate can identify the product, heat or batch, chemical analysis and applicable mechanical tests. If an EN 10204 type 3.1 inspection certificate is required, specify it in the purchase order and confirm that its contents match the delivered product.

Comparing AS/NZS 1163 With Other International Standards

When a project calls for CHS structural parts, the standard that applies shapes the whole choice about what to buy. Knowing how AS/NZS 1163 hollow sections are different from similar standards helps you avoid making mistakes that cost a lot of money.

ASTM A500/A500M-23 covers cold-formed welded and seamless carbon steel structural tubing within its stated size limits. EN 10219 addresses cold-formed welded structural hollow sections in European specifications. These standards differ in scope, grades and acceptance rules; a project substitution requires a comparison of the complete requirements, not only nominal yield strength.

An ASTM A500 Grade C product should not be treated as an automatic substitute for AS/NZS 1163 C350L0. The project engineer should assess strength, impact properties where specified, dimensions, fabrication and project approval requirements.

Applications and Benefits of AS/NZS 1163 Circular Hollow Sections

Circular hollow sections can be useful where loads act in different directions or torsion matters. Their performance relative to open sections depends on member length, boundary conditions, connection design and the relevant design checks; no single shape is lighter or stronger in every application.

The list of proven uses is long and includes many different fields:

• Building and Bridge Structures — CHS may be specified for columns, trusses and bracing after engineers check strength, stability and connections for the project loads.
• Mining Infrastructure — CHS may be used for conveyor supports and frames. Where impact performance is required, select the grade and test requirements using the project design conditions.
• Coastal and Marine Environments — Corrosion protection should be selected for the exposure environment and maintenance plan. If hot-dip galvanizing is specified, the coating requirements should be agreed with the galvanizer and checked against AS/NZS 4680:2025.

Coating performance and whole-life cost depend on exposure, surface preparation, coating thickness, detailing, inspection and maintenance. Procurement comparisons should use the actual project specification and a documented maintenance assumption.

Procurement Guide: How to Source Certified AS/NZS 1163 Hollow Sections

To get compliant AS/NZS 1163 hollow sections from a company in another country, you need to do more than just compare prices. Before making an order, structural engineers and procurement managers need to make sure that a number of factors can’t be changed.

A trustworthy supplier must be able to show:

• Grade and size availability — Confirm the required CHS grade, diameter, thickness and delivery condition against the manufacturer’s current production and order-specific offer.
• Third-party inspection acceptance — The supplier must allow SGS, Bureau Veritas, or TÜV to audit the mill and show all heat records and test coupons when asked.
• Quality management — Request the supplier’s current quality-management certificate when required by the project, and verify its scope and validity.
• Inspection documentation — State the required certificate type, traceability and test results in the purchase order; verify that the documents identify the delivered material.
• Dimensional records — Request inspection results for the ordered diameter, thickness, length and straightness against the specified edition of AS/NZS 1163.

Logistics also affect the procurement schedule. Confirm the production slot, inspection arrangements, shipping route and estimated arrival for the specific order rather than relying on a generic transit time.

Conclusion

AS/NZS 1163 provides product requirements for cold-formed structural hollow sections. Buyers should identify the specified edition and grade, verify the dimensions and required tests, and obtain the agreed inspection documents. Structural suitability and any proposed substitution should be confirmed against the project design requirements.

FAQ

1. What does the “L0” designation mean in AS/NZS 1163 grades?

The L0 designation relates to a specified impact-test requirement at 0°C. Its selection should follow the project specification and the applicable standard; temperature and dynamic loading alone do not make every L0 grade mandatory.

2. Can AS/NZS 1163 CHS sections be substituted with ASTM A500?

Not until an engineer gives written permission. The yield strength limits, impact testing requirements, and error figures for the two standards are not the same. If you replace something without first checking it, you might fail a building inspection or make the structure not meet standards.

3. What documents should I request from a supplier?

Request the inspection certificate type specified in the purchase order, relevant quality-system evidence and dimensional records. For an L0 grade, verify the impact-test results required for the product and order.

4. Is hot-dip galvanizing compatible with AS/NZS 1163 sections?

Hot-dip galvanizing can protect suitably detailed structural CHS. Agree on the preparation, venting and drainage details with the galvanizer and specify the applicable coating standard, such as AS/NZS 4680:2025.

Get Certified AS/NZS 1163 Hollow Sections From LONGMA — Request a Quote Today

LONGMA manufactures round ERW and LSAW steel pipe. For an AS/NZS 1163 circular hollow section inquiry, send the required grade, outside diameter, wall thickness, length, quantity and inspection-document requirements to info@ilongma.com. Our team can confirm production availability, applicable testing and an order-specific quotation.