Scrap metals are discarded metal objects and components that are no longer in use or have become obsolete. Scrap metals can come from a variety of sources, such as industrial manufacturing and production, demolition and construction, and discarded household items like appliances and vehicle parts. Scrap metals can be divided into two categories: ferrous and non-ferrous. Ferrous scrap metals, such as iron and steel, are those that contain iron. Non-ferrous scrap metals, on the other hand, do not contain iron and include metals such as aluminum, copper, brass, nickel, and zinc.