Abstract: With product W.T.tolerance and productivity better than any other mandrel pipe mill,the PQF mandrel mill represents the latest level of the seamless steel tube mill in terms of process design and manufacture.Based on the operation practice and process features of the PQF 3-roll retained-mandrel mill located in Tianjin Steel Tube Group,the technological advantages and equipment characteristics of the 3-roll mandrel pipe mill are elaborated and discussed.