Abstract: The invention provides a novel method of manufacturing a sacrificial anode rod assembly for cathodically protecting the internal surfaces of ferrous metal water-containing vessels, such as water heater tanks, which method provides an elongated anode rod member of a galvanically active metal and an externally threaded cap member wherein the anode rod member and cap member are connected in a tightly locked, leakproof engagement which not only results in superior mechanical and electrical properties of the anode assembly but also aids substantially in prolonging the effective life of the anode rod assembly. In the method of forming the assembly, the cap member which has an internal recess is positioned onto the extremity of the anode rod and axially aligned therewith.