Single Layer Copper-coated Steel Bundy Tube/Pipe Material :SPHC, SPCD,ST-14,BHG,BCD Outdiameter :3. ... 17mm-12mm Single Layer Copper-coated Steel Bundy Tube/Pipe Features :1) Material :SPHC, SPCD,ST-14,BHG,BCD2 ... can be used as pipes to transport the oil ,gas ,liquid.4) Surface treatment :Copper coated or zinc coated are available ...