Oerlikon Supranel CuSn description: SUPRANEL CuSn is a basic coated MMA electrode for welding phosphor bronze or tin bronze, e.g. 6-8% Sn. Postweld heat treatment is not imperative but improves the toughness of the weld metal. Suitable also for joining Cu-Zn alloys (brass) and in some cases for disimilar welding to unalloyed or low-alloy steel or gray cast iron. Also this is suitable for surfacing or repairing of gears bearings, electrode holders and for filling defects of cast iron, cast copper alloys.