PURPOSE: To form the points of pin elements to a pyramidal frustum shape by forming wedge surface relative to the axis of the pin elements, similarly deforming the points existing therebetween and repeating the stage for deforming the same.

CONSTITUTION: The tool for forming the points of the pin elements to the pyramidal frustum shape uses 8 stamps 2F, 2K respectively displaced by 45° each and respectively alternately actuates the stamps 2K and 2F arranged to be displaced by 90° each. The stamps extend perpendicularly to each other and the wedge surfaces 3 extend at a sharp angle with the axis of the pin elements in a lateral view.