Steel is not a single product. There are more than 3.500 different grades of steel with many different physical, chemical, and environmental properties.
Approximately 75% of mmodern steels have been developed in the past 20 years. If the Eiffel Tower were to be rebuilt today, the engineers would only need one-third of the steel that was originally used.
Modern cars are built with new steels that are stronger but up to 25% lighter than in the past.
Articulo of "WORLDSTEEL ASSOCIATION"