mineral / Metallic / Ferrous Structural

Circular Hollow Sections (CHS), Grade 350, various sizes

Cold-formed structural steel hollow sections with 350 MPa minimum yield strength, manufactured to AS/NZS 1163:2016 for superior structural performance in Australian conditions

Atlas code
MIN-MET-FER-008
structural-steelchsgrade-350as1163cold-formedhollow-sectioncircular
Circular Hollow Sections (CHS), Grade 350, various sizes
At-a-glance signals

Cold-formed structural steel hollow sections with 350 MPa minimum yield strength, manufactured to AS/NZS 1163:2016 for superior structural performance in Australian conditions

Overview
Executive summary

CHS Grade 350 steel sections are high-strength, cold-formed circular hollow sections offering excellent structural efficiency with a minimum yield strength of 350 MPa. Manufactured through electric resistance welding (ERW) process, these sections provide superior torsional stiffness, uniform stress distribution, and aesthetic appeal for exposed structural applications. Compliant with AS/NZS 1163:2016 Grade C350L0, they feature guaranteed impact properties at 0°C and are suitable for welding to AS/NZS 1554.1.

Best when…
  • High strength-to-weight ratio (350 MPa minimum yield)
  • Excellent torsional stiffness and resistance
  • Uniform stress distribution in all directions
  • Superior aesthetic appeal for exposed applications
  • Good weldability with appropriate procedures
  • Available with various protective coatings
  • Complies with Australian Standards AS/NZS 1163
  • Suitable for all climate zones in Australia
  • 100% recyclable at end of life
  • Proven performance in extreme weather events
  • Readily available from Australian suppliers
  • Compatible with standard connection systems
Top advantages
  1. 01 High strength-to-weight ratio (350 MPa minimum yield)
  2. 02 Excellent torsional stiffness and resistance
  3. 03 Uniform stress distribution in all directions
  4. 04 Superior aesthetic appeal for exposed applications
  5. 05 Good weldability with appropriate procedures
Top limitations
  1. 01 Requires fire protection for rated assemblies
  2. 02 Susceptible to corrosion without protective coating
  3. 03 Higher initial cost than timber alternatives
  4. 04 Thermal bridging considerations in building envelope
  5. 05 Skilled labour required for welding and fabrication
Technical
Physical ·9
Density
7850 kg/m³
Specific gravity
7.85
Porosity
0 %
Water absorption
0 %
Hardness
150
UV resistance
High // With appropriate coating
Chemical resistance
Moderate // Requires protective coating in aggressive environments
pH tolerance
4-10
Surface roughness
6.3 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
Excellent // Negligible at normal temperatures
Sustainability & Health
Embodied carbon & energy ·7
Embodied carbon
1.74
Carbon footprint
1740
Embodied energy
20.1 MJ/kg
Water footprint
64 L/kg
Recycled content
25 %
Renewable content
0 %
Circular score
9
Compliance & Fire
Fire performance ·5
Combustibility class
Non-combustible // AS 1530.1
Fire resistance level
0-120 minutes // Depends on protection system
Flame spread index
0
Smoke dev. index
0
Heat release rate
0
Cost & Lifecycle
Capex & lead time ·6
Material cost (range)
$1200-$2000 // AUD per tonne (2024-2025)
Material cost (per unit)
$1.50-$150 // AUD per metre depending on size
Lead time
1-4 weeks // Standard sections ex-stock
Lifecycle cost
$50-$100 // AUD per m² over 50 years
Annual maintenance
$5-$20 // AUD per m² for coating maintenance
Market availability
Readily available // Major suppliers nationwide
Service life & durability ·3
Expected lifespan
50-100 // Years with appropriate maintenance
Maintenance interval
5-10 // Years - Coating inspection/touch-up
Warranty period
10-25 // Years - Coating warranties available
Layer D

Where it's used

Structural columns and compression members
Architectural exposed structural steel (AESS)
Bridge construction and infrastructure
High-rise building frames
Transmission towers and poles
Stadium and arena structures
Industrial frameworks and supports
Marine structures and offshore platforms
Agricultural buildings and equipment
Mining infrastructure
Temporary structures and scaffolding
Cyclone-resistant construction
MIN-MET-FER-008 · Materials Atlas · CLAD Atlas data is reference-only. Verify against manufacturer specifications and current standards before specifying.