Silicon bronze welding wire Size: s 201 Composition: sn1 si0.3mn0.3cu rem. Description: good mechanical properties and crack resistance. Gas welding and argon arc welding of red copper. Equivalent to aws : ercu Size: s 211 Composition ·ª si3 mn1 cu rem. Description: good mechanical properties. Argon arc welding of copper alloys and mig brazing of steel. Equivalent to aws: ercusi-a Packed in cartons