wall thickness can be 28mm, size 700*400, 400*400*20 600*600, with a wall thickness of 2-25mm and a bending/distorting degree of less than 1/1000, made of straight carbon steel ,stainless steel, manganeses steel ,alloy steel and special section pipes(ellipse,lozenge,ect)2,production line of high-accuracy cold pipe and opening-type steel section; the pipe specification is 20*20-150*150,with a wall ...