Abstract: A bending machine for helically bending an elongated workpiece (T) has at least three bending rollers (2) that, being rotatable integrally with respective supporting shafts (3) with parallel axes (y), co-operate in bending the elongated workpiece (T). Each bending roller (2) is arranged to shift along its own supporting shaft (3) by way of a prismatic coupling for a limited stroke and to swing with respect to the axis of the supporting shaft (3) by way of a partially spherical body (8) forming a rotary coupling with the supporting shaft (3) in a limited amount of angular displacement according to an arc of meridian of the partially spherical body (8), so that each bending roller (2) is orientated coplanar to the elongated workpiece (T) that takes an inclined position on the basis of a desired helix pitch.