The name Corten (also written Cor-ten) is trademarked to US Steel, the inventors of the alloy. US Steel sold the Corten business to the Indian multinational ArcelorMittal in 2003 and no longer produces any Corten, but the company maintains the rights to the name.There are many producers around that produce weathering steel that is often referred to as Corten. Specifiers wanting the real thing have to pay a little more and for this they get a stamped receipt.
