It is a famous saying that, just like all the things
subjected to evolution, that which improves up on its predecessor almost
inevitably replaces it. That is exactly the case with the emergence of steel
as a clear improvement upon, if not a replacement for wrought iron.
The superiority of steel over wrought iron can be found in its strength and
consistency, which gives it a much wider range of applications than wrought
iron, including its ability to be hardened by a heat treatment. Many
metalworkers are comfortable in using this much cheaper metal both for new
work and the rehabilitation of the old.