PURPOSE: To enable the drawing of a punch before the internally chilled casting part cools thoroughly in the stage of drawing a punch for expanding pipe in the titled method by pressing and holding the insert pipe with an annular presser.

CONSTITUTION: An insert pipe 3 is placed in the prescribed position in dies 1, 2, and a pressing device 6 is advanced by the pressure fluid supplied through an inflow port 15, thereby starting expansion of a pipe 3 with a punch 4. At the same time, the step part of a piston 12 contacts with the receiving face of a piston 10, and both pistons advance cooperatively to fit throughly the punch 4 into the pipe 3, then the expansion of the pipe is completed. At the same instant, an annular presser 5 provided to the piston 10 contacts with the end face of the formed pipe 3 thereby pressing and holding the same. The internal chill in the dies 1, 2 is completed in this state. When the pressure fluid is supplied to an inflow port 16, the piston 12 retreats but the piston 10 is acted with the force in the reverse direction. The punch 4 holding the pipe 4 in pressed state is thus pulled without being influenced by the spring back of the pipe 3.