To enlarge the degree of freedom in a shape variation, to reduce the load for a movable die and a lower punch and to facilitate the change of a clearance by making movable and transferring at least one of the lower punch and the die provided in the radial direction and varying at least one of the wall thickness and the cross section shape of the material to be worked.

In a radial extruding method, the clearance between the die 1 and the lower punch 4 is changed to vary the wall thickness of the material to be worked by making the lower punch 4 movable and transferring the position. The distance from the center of the material to be worked is changed and the cross section size of a hollow extruded stock is enlarged by separating the round part of the lower surface of the die 1 from the die 1 to make the movable die 7 movable in the radial direction and changing the position wherein the flowing direction of the material to be worked is changed into the axial direction. The wall thickness and the cross section shape of the material to be worked are respectively or simultaneously varied by transferring the position of one or both of the lower punch 4 and the movable die 7.