Handy-Flo 6 is a silver-copper-phosphorus alloy used for brazing copper to copper or copper to copper alloys, most often in the HVAC industry. It should not be used on ferrous or nickel base materials due to the brittle intermetallic that forms. The phosphorus in the Handy-Flo 6 serves as a fluxing agent, so the alloy does not require flux for copper to copper joints. Flux is recommended for copper to brass joints.