LIANYUNGANG JINCHANG SPECIAL STEEL CO. Ltd. The STEEL Tube Manufacturing Factory mainly produces welded cold bending structural hollow sections in square and rectangular as per standard EN10210. The main equipments include two cold bending square and rectangular tube production lines by 200mm × 200mm and 500mm × 500mm. EFD high-frequency welder imported from Norway are used in these two lines to ensure reliable quality of welded joints. The company has also imported full-automatic continuous temperature furnace for relaxation of internal stress taking place during production. The raw materials are supplied from Wusteel and Baosteel which ensure quality of products from the beginning.