Corten steel is a high-strength weathering steel. The word “CorTen” is the trademark name given to a weathering steel alloy material originally produced by United States Steel. This steel alloy falls into the category of those that were developed to reduce or eliminate the use of coats, primers, or paints on the material to make it rustproof. When exposed to the environment, this steel forms an outer layer Platina that protects this steel from corrosion.