PURPOSE: To prevent that a defectively shaped part, such as burr or scab, is made on a section of the material, by forming the edge of the section of a cutting tool to be tapered, and making the material not to move when it is cut.

CONSTITUTION: A material 19 to be cut is led between a pair of cutting tools 18, 18 in tapered forms with cutting tool stands 14, 17 separated from each other. Screw shafts 12, 13 are synchronously rotated by a driving gear (not shown in the figure), as the upper cutting tool stand 14 and the lower cutting tool stand 17 are approaching mutually. Then, the upper cutting tool stand 14 and the lower cutting tool stand 17 approach each other, through nuts 15, 16 screwed around thread parts 12a, 12b, 13a, 13b of reverse screws, respectively. As the way of approaching is straight and the material does not move, a defectively shaped part is not made on a section of the cut material.