Brass is any alloy of copper and zinc in varying proportions. Red Brass -84.0 - 86.0% Cu,13.9-15.9% Zn, 0.05% Pb, 0.05% Fe Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive, but sometimes with other elements such as phosphorus, manganese, aluminum, or silicon. Composition - 88% copper and 12% tin Solution Brass is any alloy of copper and zinc in varying proportions. Red Brass -84.0 - 86.0% Cu,13.9-15.9% Zn, 0.05% Pb, 0.05% Fe Bronze is a metal alloy consisting primarily of copper, usually with tin as the main additive, but sometimes with other elements such as phosphorus, manganese, aluminum, or silicon. Composition - 88% copper and 12% tin.