Sebenza Steel — Right Steel. Right Time.

Specifications

Steel specification and certification

Every length of structural steel we supply is backed by certified manufacturing, documented specifications, and full traceability. Here is what that looks like in practice.

Steel Grade

Grade 350WA / S355JR: what it means for your project

We supply structural steel to two internationally recognised grade designations:

Grade 350WA

AS/NZS 3678 (Australian Standard)

The Australian Standard designation for structural steel with a minimum yield strength of 355 MPa. The 'WA' suffix denotes weldability compliance. This is the grade specified by Australian structural engineers for commercial, industrial, and infrastructure applications requiring high-strength, weldable structural steel.

S355JR

EN 10025 (European Standard)

The European equivalent designation for the same grade of structural steel. S355 denotes a minimum yield strength of 355 MPa. JR indicates room-temperature Charpy impact testing compliance. Internationally recognised by engineers and procurement teams globally.

Why both designations matter

Our steel meets both specifications simultaneously, manufactured to S355JR under ISO-certified quality management, and compliant with the equivalent Australian Grade 350WA requirements. When your structural engineer specifies Grade 350WA, we supply steel that meets that specification with full documentation.

Technical properties

Minimum yield strength
355 MPa
Tensile strength
470 – 630 MPa
Weld suitability
Suitable for welded, bolted, and riveted structural applications
Compliance
Compliant with Australian structural engineering requirements

Product Form

Solid I-beam structural steel

We supply structural steel in solid I-beam (Universal Beam and Universal Column) sections, the standard form specified for commercial and industrial structural applications. I-beam sections provide superior strength-to-weight ratio compared to hollow sections (RHS/SHS) for primary structural members including columns and rafters.

Why I-beam matters

Many budget shed and structural kit suppliers use RHS (Rectangular Hollow Section) or C-section steel for columns and rafters. Solid I-beam sections provide significantly greater structural capacity for the same member size, allowing longer spans, greater load capacity, and more efficient structural design. When we say solid I-beam, we mean exactly that.

Manufacturing and Certification

ISO-accredited fabrication: what it means in practice

Our fabrication partner operates under ISO accreditation, a certified quality management system that governs every aspect of the manufacturing process.

What ISO accreditation means for your order

  • Every production batch is manufactured under a documented quality management system
  • Raw material traceability from mill to finished product
  • Mill certificates issued with every order as standard
  • Consistent dimensional accuracy and mechanical properties across batches
  • Quality records retained for audit and project documentation purposes

Documentation supplied with every order

  • Mill certificates (mechanical and chemical properties)
  • ISO accreditation reference
  • Product specification compliance declaration
  • Dimensional inspection records on request

Australian Materials

Lysaght and BlueScope: Australian-made quality

Roof sheeting, purlins, and structural sheet materials are supplied by Lysaght and BlueScope, Australian-made products manufactured to consistent standards and trusted across the Australian construction industry.

Lysaght products we supply

  • ZINCALUME® and COLORBOND® roof sheeting
  • Structural purlins and girts
  • Roof and wall cladding systems

Engineering

Australian engineering behind every supply

Our structural steel supply is backed by Australian engineering expertise. We work with Australian structural engineers who understand AS/NZS Standards, Australian wind regions, and the specific requirements of construction in Australian conditions.

Wind regions (AS/NZS 1170.2)

Region A
Standard wind loads: southern and inland Australia
Region B
Intermediate wind loads: coastal areas
Region C
Higher wind loads: northern coastal and some inland areas
Region D
Cyclonic wind loads: tropical coastal areas

Ready to discuss your project?

Our team can confirm specifications, documentation requirements, and availability for your project.