To provide a piercer capable of improving the service life of a plug and the quality of the inside surface of a material to be pierced in the piercing stage of a metallic long colume body.
In this device, the plug 1 is made into the shape having a conical base which shares the axis of symmetry with its external size or a cylinder- shaped through hole which is continued to the conical base, composed of a ceramic material excellent in wear resistance and fouling resistance or a cermet material containing ≥50%, in total, of ≥1 kinds of ceramics such as carbide, boride and oxide. By using a fixing rod 3 in which a locking part is provided at one end and a fixing part is provided at another end, the plug 1 is made into the structure for connecting and fixing the plug 1 to a joint 2 on which a cylinder-shaped through hole which shares the axis of symmetry with the external size. By this device, the ceramic material and cermet material excellent in the fouling resistance and wear resistance are applicable to the plug practically without problem and the service life of the plug 1 and the quality of the inside surface of the material to be pierced are improved.
UCHIDA HIDE
HAMAUZU SHUICHI
