Abstract: Control unit for torch-cutting machines consisting of bars which grip the sides of the cast product, and at least one cutting-torch carriage, movable in a direction at right angles to the movement of the machine. This control unit consists of a first element carried by the cutting-torch carriage and a second element which combines with the first to halt the carriage when it reaches a predetermined position.This unit is characterized by the fact that the second element is kinematically linked to the grip-bar situated on the side of the cast where the cut will begin, in such a way that the movements of the grip-bar move this second element in a direction parallel to the path of the cutting-torch carriage, at a speed equal to and in the same direction as the component, parallel to the path of the cutting-torch carriage, of the speed of the end of the grip-bar which comes into contact with the cast product.The invention can be used in the field of continuous casting of metals, particularly steel.