CYLINDRICAL PRODUCT, ITS MANUFACTURING METHOD AND MANUFACTURING APPARATUS

PROBLEM TO BE SOLVED: To provide a cylindrical product in which an outer circumferential surface of a side part is smooth and hardly broken. SOLUTION: The cylindrical product has a cylindrical side part having four outer peripheral surfaces along a parallelogram and a bottom part formed on one end of the side part, and the four outer peripheral surfaces of the side part are rolled by a roller. In a manufacturing method of the cylindrical product, the cylindrical product having four outer peripheral surfaces with the side part being along the parallelogram is formed out of a cylindrical material with the side part having four outer peripheral surfaces along the parallelogram by the rolling of the roller. In the manufacturing method of the cylindrical product, the cylindrical material having the four outer peripheral surfaces with the side part being along the parallelogram is rolled to manufacture the cylindrical product having four rolled outer peripheral surfaces with the side part being along the parallelogram while a core is inserted between at least two rotating rollers parallel to each other. COPYRIGHT: (C)2008,JPO&INPIT