DMH UNITED STEEL INDUSTRY CO.,LTD(USI Group) is one of the largest steel pipe groups in China. Established in1989,headquartered in Suzhou City,Jiangsu Province.USI group has 20 branch companies,total assets:1 billion dollars,more than 10000 employees, and 6 factories(locate in Tianjin ,Suzhou and Cangzhou city) for producing steel pipes(ERW,SSAW,LSAW,SMLS,Stainless Steel Pipe, etc..)