Tianjin Didoo Imp&Exp Co.Ltd was, founded in 2004 year with registered capital of RMB 3 milion, we are specialized in manufacture and supplying Tube-welding cladding bimetal wire�Copper Clad Steel Wire, Copper Clad Aluminium Wire and their related products. We are locating in the beautiful coastal city Tianjin , where is the center of the Bohai Sea Economic Sphere in North China, we enjoy convenient transportation and preferable exporting policies. We adopt the advance technology of tube-welding cladding production precess, the process is clad planished copper belt concentrically on outer surface of the the core line(steel wire or aluminium wire) and weld in shape, then via drawing and heat treatment, there forms a firm metallurgical bonding between the copper layer and core line(steel wire or aluminium wire). Its surface is bright and smooth without flaw, This kind bi-metal has excellent electrical conductivity and corrosion resistance of copper, moreover, the copper-clad steel wire has high-performance of steel, the copper-clad aluminium has low density performance of aluminium. As for the copper clad steel, when certain high-frequency signal transmits, the high-permeability of steel brings the reflection effect of the electromagnetic waves on the steel � copper interface, and the impendance and return loss are less than the solid copper with the same cross-sectional area. More than 30% of our products are exported to all around the world, We can implement most internation standars, including ASTM B 452, ASTM B 227, ASTM B 869, ASTM B 520, ASTM B910/B910M, BS 4087, OCT 4775-91, GJB 882A-2002, YD/T 722-94 or the standards and requirements of users.