PURPOSE: To make giving of draft in forging unnecessary by providing a mechanism having a lower die that rotates around a main shaft, an upper die having conical working face and a rotation axis inclined to the main shaft and a roll that forms outer diameter of the material.

CONSTITUTION: A lower die 1 is made to rotate around a main shaft T, and an upper die 2 has a conical working face 3 and the center axis P of rotation makes an angle θ to the main shaft T. A material 4 of specified weight is placed between the lower die 1 and upper die 2. An external form forming roll 6 that forms outer diameter form of the material 4 is provided outside 5 of pressure receiving part of the material 4. That is, the forming roll 7 is pivoted rotatably on a roll support 8. By this way, providing of draft becomes unnecessary. Outer diameter form of the product can be changed by changing the form of the forming roll 7. Forging according to the weight of the material 4 can be performed by moving the forging roll 7 with a driving equipment 9 and changing the position of a stopper 11 properly.