A press (1) is described, for molding an ingot made of thermoplastic or thermosetting material, comprising a basement (10) integral with risers (20), a first and a second plane (30, 40) relatively sliding with respect to the risers (20), by means of first and second hydraulic cylinders (50, 60), respectively adapted to allow opening and closing a mold formed of a first half-mold fastened to the first plane (30) and a second half-mold fastened to the second plane (40), comprising actuators (70) adapted to exert a force whose direction is equal to or opposite with respect to the direction of the force adapted to allow opening or closing the mold; the first plane (30) connected to the basement (10) is moved by means of the first hydraulic cylinders (50) and of the actuators (70), while the second plane (40) is blocked by means of a blocking apparatus (80).