Weathering steel (often referred to as Corten A or Corten B Steel) is an alloy steel that is often used in the construction industry. It is well-known for its rust-like appearance, which is caused by the metals chemical composition. This blog post will outline some of the benefits of using weathering steel for construction.

Corrosion Resistance

Weathering steel is an alloy of copper, nickel, and chromium, and this is what gives the steel the high level of resistance to atmospheric corrosion. For other types of steel, moisture and air can cause them to rust at varying rates which provide no protection to the material. This type of rust is extremely porous and can fall off the material after time.

Weathering steel does still undergo the initial rusting process, but the alloying elements create a consistent and stable layer of rust that adheres to the material. This rust layer provides protection against further encounters of moisture and air.

The corrosion resistance of this metal ensures that it has a long lifetime, making weathering steel an economic choice for the construction industry.


The protective rust layer that covers weathering steel is a distinct orange-red color that is often considered aesthetically pleasing. This unmistakable appearance is sometimes the sole reason for the choice of weathering steel.

Learn More: Corten Steel Structures Around the World

Examples of structures where weathering steel was used for appearance purposes is Echigo-Matsunoyama Museum of Natural Science, where the designer wanted the museum to look like a ruin and contrast against the color of the snow.

The appearance of the steel also reduces the speed of construction, as the requirement to paint the steel is eliminated.


For the construction industry, the yield and tensile strength of a material is critical, especially in structures like bridges and buildings. Weathering steel provides these properties, in addition to ductility and toughness.

Maintenance and Safety

The high level of corrosion resistance that weathering steel exhibits means that maintenance is reduced as the material is subjected to less damage. Only periodic cleaning and inspection is required. This quality makes weathering steel the ideal choice for structures where future maintenance will be dangerous and difficult, and disruption needs to be kept to a minimum.

The reduction of maintenance helps to improve safety as the risks associated with it are minimised.

Weathering Steel from Masteel

Masteel are major stockholders of weathering steel, and we can ship our products globally with a quick-turnaround. Depending on the application, we can produce steel in a range of plate widths and thicknesses.

Learn More: Corten Steel Products from Masteel

If you would like any more information about weathering steel, please contact us.