Corten Steel

Corten Steel to a Commercial Office Building

‘Corten’ is the genericised trademark for Weathering Steel. The product COR-TEN® is a trademarked name owned by U.S. Steel who were the first to make this weathered steel product popular.


Corten Steel Window Corner Close Up

What is Corten/Weathered Steel?

COR-TEN steel is just a trademarked name for Weathered Steel which is a group of steel alloys developed to create a corrosion resistant steel that didn’t need painting or finishing.

It is created by accelerating the natural oxidisation of steel to form a layer of iron oxide, or rust, on the surface of the steel frame. This rusted outer coating seals the steel profile, preventing further oxidisation or corrosion to the steel over time.

What are the benefits of Corten/Weathered Steel in windows and doors?

Weathered steel is currently enjoying and architectural resurgence, being used as window frames and building cladding on many high profile architectural designs. The textured and tactile finish achieved from Corten offers building designs contrast against other more minimal building finishes.

Corten steel offers the same tensile strength as mild steel but offers a resistance to corrosion that is 6-8 times higher than traditional steels.


Are there any drawbacks of using Corten Steel?

The surface of Corten is rusted and textured. Inevitably there will be a small amount of rust which will come off from this surface and settle. When rained on this could cause staining on very porous materials.

One of the reasons that designers love Corten is that no one piece is the same and each element will have its own character and change differently over time. That does mean that no one piece of Corten will be the same and an elevation of Corten framed windows will age differently depending on their orientation to the sun and how sheltered they are.

What are the uses of Corten Steel?

Corten steel is widely used as a cladding material and can also be used to create any of the Mondrian® CWS window and door frames for a unique design. We have a set of Belgium doors at our showroom in Amersham that are created with thermally broken Corten frames. 


Copyright Simon Maxwell Photography