It is an alloy of tin, manganese, aluminum, nickel, iron, silicon and other elements of the impurities that give the appropriate physical and mechanical properties. Depending on the percentage of copper, alloy differ in color from red to pale yellow. Brass is cheaper than copper, tough and well cast. Brass with 38% zinc impurity is very ductile and slightly stronger than copper. By increasing the amount of zinc, brass increases hardness, improves moulding properties, but reduces ductility.