Corten steel is a high-resistance alloy containing copper, chrome and phosphorous. It became popular in the mid 1930’s used mainly for heavy construction and sculptures. It is a material that is characterized by being highly resistant to corrosion with high tensile strength. These alloys are self-protective through the formation of a superficial coating that prevents the progressive extending of the corrosion process. The oxidation process can be accelerated through a process done in house where oxidizing is done by hand over a 2-3 week period. The resulting finish is a material with unique coloring of warm shades of brown and orange. Thanks to Brombal’s innovative and technological advancements, we were the first manufacturer to produce windows and doors from this material which is highly appreciated by the architectural community.