mineral / Metallic / Ferrous Structural

Rectangular Hollow Sections (RHS), Grade 350, various sizes (Specified by size & wall thickness)

Cold-formed structural steel hollow sections to AS/NZS 1163 with 350 MPa minimum yield strength, providing excellent strength-to-weight ratio for structural applications in Australian construction

Atlas code
MIN-MET-FER-007
mineralmetallicstructural-steelhollow-sectiongrade-350AS-NZS-1163cold-formed
Rectangular Hollow Sections (RHS), Grade 350, various sizes (Specified by size & wall thickness)
At-a-glance signals

Cold-formed structural steel hollow sections to AS/NZS 1163 with 350 MPa minimum yield strength, providing excellent strength-to-weight ratio for structural applications in Australian construction

Overview
Executive summary

RHS Grade 350 are cold-formed, electric resistance-welded steel hollow sections manufactured to AS/NZS 1163:2016. The '350' designation indicates a minimum yield strength of 350 MPa, making these sections suitable for high-strength structural applications. The rectangular profile offers excellent torsional rigidity and compression resistance, with standard sizes ranging from 50x20mm to 400x300mm with wall thicknesses from 1.6mm to 16mm. The material features a ferrite-pearlite microstructure providing optimal strength and ductility for welding and fabrication.

Best when…
  • High strength-to-weight ratio optimising structural efficiency
  • Excellent torsional rigidity and buckling resistance
  • Suitable for welding with standard procedures
  • Consistent mechanical properties through cold-forming process
  • 100% recyclable with established recycling infrastructure
  • Available in dual-grade options (C350/C450) for design flexibility
  • Compatible with all standard connection methods
  • Aesthetic appeal for architectural exposed applications
  • Lower embodied carbon than concrete alternatives
Top advantages
  1. 01 High strength-to-weight ratio optimising structural efficiency
  2. 02 Excellent torsional rigidity and buckling resistance
  3. 03 Suitable for welding with standard procedures
  4. 04 Consistent mechanical properties through cold-forming process
  5. 05 100% recyclable with established recycling infrastructure
Top limitations
  1. 01 Requires fire protection for rated assemblies
  2. 02 Susceptible to corrosion without protective coatings
  3. 03 Thermal bridging in building envelope applications
  4. 04 Higher initial cost than timber alternatives
  5. 05 Limited availability of very large sections
Technical
Physical ·9
Density
7850 kg/m³
Specific gravity
7.85
Porosity
0 %
Water absorption
0 %
Hardness
150
UV resistance
High // Inorganic material unaffected by UV
Chemical resistance
Moderate // Requires protection in aggressive environments
pH tolerance
4-10
Surface roughness
3.2 µm
Mechanical ·7
Tensile strength
430 MPa
Compressive strength
350 MPa
Flexural strength
350 MPa
Shear strength
200 MPa
Poisson's ratio
0.3
Impact resistance
27
Creep resistance
Negligible below 400°C // Temperature dependent
Sustainability & Health
Embodied carbon & energy ·7
Embodied carbon
14.5
Carbon footprint
1.85
Embodied energy
25 MJ/kg
Water footprint
28 L/kg
Recycled content
25 %
Renewable content
0 %
Circular score
85
Compliance & Fire
Fire performance ·5
Combustibility class
Non-combustible // AS 1530.1
Fire resistance level
0/-/- unprotected; up to 240/-/- with intumescent coating // AS 1530.4
Flame spread index
0
Smoke dev. index
0
Heat release rate
0
Cost & Lifecycle
Capex & lead time ·6
Material cost (range)
1800-2500 // AUD/tonne - 2024 market prices
Material cost (per unit)
15-45 // AUD/m depending on size
Lead time
1-3 days ex-stock, 2-4 weeks fabricated // Typical
Lifecycle cost
Competitive over 50+ year design life // Qualitative
Annual maintenance
2-5 // AUD/m² for coating maintenance
Market availability
Readily available // Stock items
Service life & durability ·3
Expected lifespan
50-100 // years with appropriate protection
Maintenance interval
5-10 // years for coating inspection
Warranty period
10-25 // years for galvanised coatings
Layer D

Where it's used

Structural frames in commercial and industrial buildings
Column and beam applications in multi-storey construction
Roof trusses and portal frames
Architectural features and exposed structural elements
Seismic bracing systems
Bridge and infrastructure components
Temporary structures and scaffolding systems
Agricultural and mining equipment frames
Bollards and protective barriers
MIN-MET-FER-007 · Materials Atlas · CLAD Atlas data is reference-only. Verify against manufacturer specifications and current standards before specifying.