ERCuSi-A Silicon Bronze Welding Rod ANSI/AWS A5.7 Class ERCuSi-A ASME SFA-5.7 Class ERCuSi-A Description and Application Silicon Bronze is a copper alloy wire containing 3% silicon and used for GMAW, GTAW or Oxyacetylene Welding of copper, brass, bronze, steel and cast iron. Silicon Bronze is best known for welding plain or galvanized steel sheet metal in the manufacturing of steel cabinets, metal furniture and ductwork. Weld deposits demonstrate high strength, excellent corrosion resistance and good weldability, making this wire suitable for surfacing parts in corrosive environments. Approximate Melting Temperature: 1866°F (1019°C) Average As-Welded Brinell Hardness: 80 – 100 Brinell Tensile Strength: 51,000 psi Density: 0.308 lbs/in3 Oxyacetylene Welding: The oxyacetylene gas flame should be slightly oxidizing (neutral) to keep the weld puddle small in order to allow fast solidification and this will also minimize cracking; use a borax type flux both before and during welding; preheating is not recommended.