PURPOSE: To correct bending the thickness deviation caused by various factors at the time of drawing by detecting distribution of die face paressure in the circumferential direction that acts on the die during drawing work of a pipe bar material and adjusting the die to a required direction.

CONSTITUTION: Five pressure detectors (load cells) 11 are arranged uniformly in the circumferential direction around a center axis (a) of die 8 hole between the front face of a die stand 10 and the rear face of a die sheet 9 carrying a die holder 7 that supports a die 8. The tip of the pipe is extracted in the direction of A acrss a die 3. Distribution of die face pressure in the circumferential direction that acts on the die 8 during the drawing work is detected by the cell 11. A die supporting device 13 that gives the die the required amount of tilting in required direction basing on the distribution of face pressure is provided around the axis (a) between the front face of the stand 10 and rear face of sheet 9 flange part 12 is provided in correspondence to the cell 11. For instance, above- mentioned tilting of the die 8 is given and adjusted by a hydraulic cylinder 16 in which the tip of a piston rod 15 is fixed on the back of the flange part 12 in a concavity 14.