The primary Australian standard for structural steel is governed by Standards Australia through a series of AS / AS-NZS standards that define material grades, dimensions, fabrication, and construction requirements.

Main Australian Standards for Structural Steel

1. AS/NZS 3679 – Structural Steel

This is the core material standard for hot-rolled structural steel used in buildings and civil engineering.

• AS/NZS 3679.1 – Structural steel bars and sections

• AS/NZS 3679.2 – Structural steel plates

Common steel grades:

• Grade 250

• Grade 300

• Grade 350 (most widely used in Australia)

2. AS/NZS 5131 – Structural Steelwork

This standard covers fabrication and erection of steel structures.

It defines:

• Execution classes (EXC1–EXC4)

• Welding quality levels

• Inspection and compliance requirements

3. AS 4100 – Steel Structures

AS 4100 is the design standard for steel structures in Australia.

It specifies:

• Load combinations

• Member design

• Connection design

• Structural safety and serviceability

4. AS/NZS 1163 – Cold-Formed Structural Steel

Used for light steel framing and hollow sections.

Common grades:

• C250

• C350

5. AS/NZS 1554 – Structural Steel Welding

This standard regulates welding procedures and qualifications for steel structures.

Which Steel Grade Is Most Common in Australia?

For most structural steel buildings:

• AS/NZS 3679 Grade 350 is the most commonly specified

• It offers a good balance of strength, weldability, and cost

Why Australian Steel Standards Matter

Compliance with Australian standards ensures:

• Structural safety

• Earthquake and wind resistance

• Legal and insurance compliance

• Approval from local authorities

• Long-term durability

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