FORGING METHOD AND MOLD FOR FORGING

A forging method according to the present invention is characterized by including the steps of placing a work W having a first shape which is a rectangular hexahedron in a work space 45 of a forging die 20 which has a rectangular opening, which is formed by rectangular plane wall portions, and which is provided with the work space 45 to hold the work in a placement step and applying a plastic strain to the work W by deforming the placed work W into a second shape which is a rectangular hexahedron in a working step, wherein the placement step and the working step are performed at least two times. For example, the work is press-deformed in the work space of the forging die and, thereby, the shape stability can be further ensured. Also, the forging die 20 has a structure in which a plurality of die parts are fitted into the inner periphery of the outer die, so that, for example, the stress applied to the inner die 50 during pressurization of the work W can be dispersed to the outer peripheral side more evenly by the plurality of die parts and breakage of the die and the like can be further suppressed.