Abstract: Cardboard boxes are formed starting from a stamped sheet which is vertically pushed by a descending core (13) for folding the sectors (6) that are going to form the sides and those that are going to form the front ends (7), including equipment for folding of the extensions and/or flaps (8, 10) which are folded on the front ends and/or sides. The mold is intended to shape boxes having an upper horizontal bridge (9) in the sides (6), bridges presenting flaps (10) which fold over the front ends (7), being fixed to the outer face of them, with these front ends (7) in turn presenting end extensions (8) which are folded in the inner face of the sides (6). The mold includes runners (11) adjustable in height, permitting to fold the end extensions (8) of the front ends (7), also having wedges in ramp (14) and presses (15) with an inclined plane (16), for folding the flaps (10) of the upper bridges (9) of the sides (6), these flaps (10) being folded on the front ends (7).