Corten
Corten, often referred to as weathering steel, is a high‑strength alloy designed to develop a stable, protective oxide layer when exposed to the elements. This controlled surface oxidation forms a dense patina that slows further corrosion, allowing the material to perform exceptionally well outdoors without the need for paint. Its long‑term durability depends on exposure to alternating wet and dry conditions, as this cycle is essential for the patina to mature.
Corten has an expected life span of 30+years, however in environments where moisture is constant or salt levels are high, the protective layer may not form correctly, reducing the steel’s expected lifespan.
As a steel product, Corten is inherently non‑combustible and behaves similarly to structural carbon steel in fire conditions. This makes it suitable for applications where fire resistance is required, and it is commonly used in architectural and landscaping projects where both safety and longevity are priorities.
One of the defining characteristics of Corten steel is its evolving appearance. The surface gradually shifts from bright orange tones to deeper, richer browns as the patina develops. This finish is intentionally variable, and colour uniformity cannot be guaranteed. During the early stages of weathering, runoff can stain nearby surfaces, so installations must be detailed to manage drainage and protect adjacent materials. Over time, the patina becomes more stable and visually consistent, giving the steel its distinctive, natural aesthetic.
Corten is widely used in architectural cladding, garden structures, sculptures, bridges, and outdoor products where a combination of strength, low maintenance, and visual impact is desired. While it offers excellent performance in the right conditions, it must be detailed carefully to avoid trapped moisture, soil contact, or areas where water cannot drain freely. With proper design and exposure, Corten provides a long‑lasting, visually striking material that continues to develop character throughout its service life.
Finish Properties
| Property | Unit | Value | Test Standard |
|---|---|---|---|
| Fire classification | A1 | BS EN 13501 |
