Head (1) for a mowing machine, with rotation axis and body (3) that includes two parts (3A, 3B) coupled to each other, at least one outlet hole (9A) in one of said parts (3A, 3B ) through which one end (F1, F2) of a cutting cable exits the body (3), said body (3) having a substantially cylindrical perimeter wall, on which at least one of said holes of output (9A), said body (3) housing at least one reel for said cutting cable, an elongation mechanism having been provided to lengthen or restore the original length of the projecting ends (F1, F2) of the cutting cable, characterized in that, adjacent to said exit hole (9A) or to each of said exit holes (9A) through which the cutting cable exits and at least one side of said hole (9A), a projection is provided radial (11) to protect said cutting cable, which comes out of said exit hole (9A), so that and, in case of breakage of the cutting cable, the cut end of said cutting cable remains in a projection position, at least, for a length equal to the maximum radial dimension (R) of the projection towards the outside of the head (1), avoiding the recovery of the cutting cable inside the body (3)； so that said projection (11) - is disposed in said cylindrical perimeter wall, at a certain distance from said outlet orifice (9A), - is in the form of a tangential fin with a radial dimension that develops from a point (11B) of connection to the body (3) of the head, towards a point (11C) of maximum proximity to the outlet hole (9A) of the cutting cable.Cabezal (1) para una máquina segadora, con eje de rotación y cuerpo (3) que incluye dos partes (3A, 3B) acopladas entre sí, como mínimo, un orificio de salida (9A) en una de dichas partes (3A, 3B) a través del cual un extremo (F1, F2) de un cable de corte sale del cuerpo (3), teniendo dicho cuerpo (3) una pared perimetral sustancialmente cilíndrica, sobre la que está dispuesto, como mínimo, uno de dichos orificios de salida (9A), alojando dicho cuerpo (3), como mínimo, un carrete p
