Usually a 99 to 99.9% pure copper with a fractional percentage of one or more deoxidizing agents such as phosphorus, silicon, manganese, cadmium, zinc or aluminum. All of these agents act to reduce the cuprous oxide and thus entirely purge the metal of oxygen. Deoxidized copper is preferred when the metal is to be welded because weaknesses due to the cuprous oxide are avoided. See COPPER ALLOY WELDING.
