Although steel was first discovered around the 3rd century BC in ancient India, Sir Henry Bessemer created a way to standardize the process in 1856. Steel made prior to this time was called crucible steel, it was costly to make but of high quality.
Steel made using the Bessemer process is easy and cheap to mass produce. The amount of carbon added to iron changes it from wrought iron, to steel, to cast iron, each being a progressively harder metal. The Bessemer process uses a converter to force a blast of air into molten-pig iron; and, this increases the carbon content. Robert Mushet later refined the technique, by adding spiegel a compound of iron, carbon, and manganese, to help streamline the process.