Abstract: In a forming press, a die comprises a pair of half-dies, supported by a bed, able in turn to support an element to be deformed permanently in opposition to the thrust exerted by a forming punch. The die is provided, for each of the half-dies, with two racks associated to the respective half-die and to the bed, which are provided with at least a pair of oblique teeth, set side by side, and associated in mutual opposition with teeth of the one inserted between the teeth of the other. The teeth of the conjugate racks are mutually coupled simultaneously on at least two parallel and oblique contact planes, and mesh in a manner able to determine the variation of the distance between the half-dies in correspondence with the relative translation of the racks effected longitudinally to the half-dies themselves.