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COR-TEN® Weathering Steel

Coen Steel are the largest COR-TEN®sheet steel Stockholder in Ireland currently offering 1.5mm up to 15mm. COR-TEN®has fast become one of the most in demand materials in recent years due to its aesthetic appeal and practicality over standard mild steel.

Product Information

Corten Steel is now becoming the trend setting material in all aspects of architecture and engineering. Its distinctive appearance and naturally oxidizing finish make it highly appealing for numerous architectural applications.

Bend it. Perforate it. Mix it. There are endless opportunities to bring a natural beauty to the environment it is located in.

Corten Steel, often known as Weathering Steel, is a set of steel alloys designed to eliminate the need for painting and to create a stable rust-like appearance after prolonged exposure to the elements. Compared to other steels, COR-TEN® steel has higher resistance to atmospheric corrosion.

COR-TEN® is resistant to the corrosive effects of rain, snow, ice, fog, and other climatic conditions by developing a covering of dark brown oxidation over the metal, which prevents deeper penetration and eliminates the need for painting and expensive rust-prevention maintenance over the years.

Typical applications are sculptures, landscaping edging, planter boxes, gates, railings, and many others.

Features & Benefits

The Oxidation of Corten Steel

During oxidation, the colour varies from, at first, orange to a reddish-brown when the patina has stabilised. Under normal environmental conditions, this occurs in 18-36 months. Essential factors for the correct formation of the patina are alternate cycles of dry/wet, contact with the atmosphere and the catalytic action of sunlight, combined with the absence of permanent stagnant water. It is inadvisable to leave COR-TEN® steel surfaces in marine environments rich in chlorides, as they do not promote oxidation and formation of the protective rust patina. If you do not want to wait for the protective oxide to form naturally, sandblasting or accelerated oxidation treatments can be carried out.

Environmentally friendly

With its anti-corrosive properties, COR-TEN® minimizes the need for maintenance and corrosion-prevention treatment, contributing significantly to low maintenance costs throughout the product lifecycle. In addition to low maintenance costs, the reduced need for corrosion prevention means less use of paint and solvents, making COR-TEN® an environmentally friendly choice of steel.

Easy to fabricate

The high strength of the steel in combination with these properties makes it easier to Fabricate. To obtain the same corrosion resistance in the weld as in the base metal, special filler metals should be used.

Downloadable Assets

What is SSAB Weathering

SSAB Weathering is our wide range of high-strength weather-resistant steels and COR-TEN® grades that provide minimum total life cycle costs thanks to low or zero maintenance requirements.


Do you have any questions about Coen Steel products? As industry leaders in steel fabrication in Ireland, we have compiled some useful information about our products and services. Can’t find what you’re looking for? Contact our team of experts to discuss your needs.

Generally, COR-TEN® steel will patina or rust within 6 months of atmospheric exposure. Most weathering steel types need cycles of wet/dry weather to develop and oxidize. With the protective rust that provides corrosion resistance, COR-TEN® steel can last upwards of a few decades to over 100 years.

COR-TEN® resists the corrosive effects of rain, snow, ice, fog, and other meteorological conditions by forming a coating of dark brown oxidation over the metal, which inhibits deeper penetration and negates the need for painting and costly rust-prevention maintenance over the years.

While the corrosion resistant properties of weathering steel allow it to be used unpainted in structural and architectural applications, it CAN be painted. However, the surface requires proper cleaning, preparation and material to achieve a painted appearance.

COR-TEN® steel has a distinctive orange color, which is caused by the chemical composition forming a protective rust layer when exposed to extreme environments. There are two main grades of COR-TEN® steel: COR-TEN® A and COR-TEN® B.

COR-TEN® A is used in outdoor applications that are exposed to changing weather conditions such as external claddings and sculptures but is not recommended for load bearing applications. COR-TEN® B is generally used for the heavy-duty load bearing structures such as buildings, bridges etc.

Welding on steel that is COR-TEN® is relatively as similar as low carbon steel. The only precaution the welders need to take is regarding the filler or electrode which is different from mild steel.

COR stands for corrosion resistance and TEN stands for tensile strength.

COR-TEN® steel is economical, long lasting, easily recyclable and is a zero-maintenance finish, making it a very sustainable material and eco-friendly material.

There are many weathering steels but there is only one COR-TEN® . In principal Cor-Ten® and Weathering steels are steels with improved resistance to atmospheric corrosion. Cor-Ten® is a trademark from US Steel since 1933.  Standardized weathering steels follow the same principal; however, they cannot replicate exactly the Cor-Ten® spec.