Alloy steels contain varying proportions of alloying elements (such as manganese, silicon, nickel, titanium, copper, chromium, and aluminum) to control steel properties such as hardenability, corrosion resistance, strength, formability, weldability, or ductility . The differences are somewhat uniform, but for the sake of distinction, all alloy steels over 8% by weight, not carbon and alloys, are considered high-alloy steels. Alloy steel is harder, more durable, and more resistant to corrosion. Alloy steels with moderate to high carbon content are difficult to weld. However, if the carbon content is reduced to 1% to 3%, this alloy metal can achieve higher formability and weldability, thereby increasing strength.