About COR-TEN® · Weathering steel
More than a rusted finish.
COR-TEN® is a genuine weathering steel designed to form a dense, protective patina when exposed to alternating wet and dry conditions. It's used for cladding, facades, landscaping and fabrication where a natural weathered finish is required.
- PatinaSelf-protecting surface
- Wet · dryBest weathering cycle
- SSABGenuine COR-TEN® supply
- 18–24 monthsTypical time to stabilise
The material
Steel engineered to weather.
CORrosion resistance + high TENsile strength
Where the name comes fromNot ordinary rusted steel
COR-TEN® is an alloyed weathering steel containing elements such as copper, chromium, nickel and phosphorus. These help the first oxidation form a tight, fine-grained oxide layer, rather than the loose, flaking rust you see on mild steel.
The surface is functional
That oxide layer, the patina, acts as a barrier that slows further corrosion by limiting oxygen and moisture reaching the steel underneath. Once stabilised, typically after 18–24 months outdoors, it needs no paint or coating.
The wet / dry cycle matters
COR-TEN® needs to dry out fully between rain events. Standing water, poor drainage or constantly humid conditions can stop the patina stabilising. See design considerations →
The weathering journey
From raw steel to protective patina.
- 01
Fresh material
Raw steel
Supplied in its raw form: dark grey, blue-grey or mill-finished before exposure.
Before exposure
- 02
Early oxidation
Orange-brown
Once exposed to rain and air, the surface starts developing its rusted look.
Early exposure
- 03
Developing patina
Colour variation
Repeated wet and dry cycles make the oxide layer denser. Uneven colour and streaking are normal.
Developing stage
- 04
Stabilised finish
Mature layer
The patina matures into a darker, settled surface that helps protect the steel beneath.
Typically 18–24 months
Important: the patina forms best when COR-TEN® can fully dry between wet periods. Airflow and drainage matter.
Common applications
Where COR-TEN® gets used.
Architectural facades
Cladding & panels
Landscape features
Outdoor applications
Fabrication supply
Images are for application reference only. Corten Australia supplies raw COR-TEN® sheets and coils. Fabrication, installation and detailing are handled by the buyer, fabricator or project team.
About the manufacturer
Genuine COR-TEN® by SSAB.
SSAB is a Nordic steel manufacturer with origins in Sweden and Finland, known worldwide for advanced high-strength, structural and weathering steels.
COR-TEN® is a registered trademark of U.S. Steel Corporation. SSAB produces it under licence, meeting the original chemical and mechanical specification. Only material produced under this licence can carry the COR-TEN® name. Steel sold as "corten" without it is generic weathering steel and may not meet the same standard.
- 1978Established
- NordicSweden & Finland
- LicensedGenuine COR-TEN®
- GlobalSteel operations
Trade & bulk enquiries
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