Flexi Says: Alloys are made in a blast furnace by mixing different metals. Steels are a very important class of alloys. The many types of steels are primarily composed of iron, with various amounts of the elements carbon, chromium, manganese, nickel, molybdenum, and boron. Steels are widely used in manufacturing appliances like refrigerators and washing machines which are expected to be strong and durable over several years.