Abstract: With the 369 mm and 451 mm passes,the PQF mill failed to produce tubes within the size range of Φ355.6~370 mm.Addressing this problem,a 382 mm pass is designed and developed by Tianjin Steel Pipe Corp.,Ltd.The 2-year trial and massive productions have proven that using the 382 mm pass,the mill is capable of rolling tubes with sizes of Φ356(355.6) mm,365 mm,and 368 mm which have satisfactory and consistent wall thickness tolerance and inner and outer surface quality.