PIERCING MACHINE AND METHOD FOR MANUFACTURING SEAMLESS METALLIC TUBE USING SAME

A piercing machine is provided that can suppress a temperature difference between a fore end portion and a rear end portion of a hollow shell after piercing-rolling or after elongation rolling. A piercing machine (10) includes a plurality of skewed rolls (1), a plug (2), a mandrel bar (3) and an outer surface cooling mechanism (400). The outer surface cooling mechanism (400) is disposed around the mandrel bar (3) at a position that is rearward of the plug (2), and with respect to an outer surface of a hollow shell (50) advancing through a cooling zone (32) which has a specific length in an axial direction of the mandrel bar (3) and which is located rearward of the plug (2), as seen from an advancing direction of the hollow shell (50), the outer surface cooling mechanism (400) ejects a cooling fluid (CF) toward an upper part of the outer surface, a lower part of the outer surface, a left part of the outer surface and a right part of the outer surface of the hollow shell (50) to cool the hollow shell (50) inside the cooling zone (32).