Recycled steel accounts for 46% of the iron resource of the steel industry in the world and has generated a new production route, based on the electric arc furnace, that produces 33% of the world steel output. Recycling is fully integrated in the market economy and has gained experience and technologies that allow 75% of the steel of end of life products to be effectively recycled. Furthermore, allowing for a modicum of cautions, this recycling is sustainable, which means that it may be repeated indefinitely, a feature that can be claimed by few materials. The use of scrap to produce steel requires 75% less energy than the integrated production route, that means 92% less energy than what is required to produce the same amount of aluminium. The electric arc furnace also allows the recycling of zinc, which is easily separated from the galvanized steel sheets used in construction and automotive industry. A large project federating the contributions of industry and academia, led by USINOR, has been carried out from 1995 to 2000 to support the sustainable recycling of steel: the main results of the “Iron Cycle” are reported in this paper.