Abstract: This steering-wheel shaft, having a cylindrical tubular body (1) with a circular cross-section, has a profiled part (8) forming a lock element. In this part (8), longitudinal grooves (10), having a width which corresponds to that of a locking catch, have a depth at least equal to the thickness of the wall of the initial tube and are separated by solid ribs (12). On the inner face of the element (8), projections define between them V-shaped grooves whose peaks correspond substantially to the mid part of the ribs. Each rib (12) thus has a sufficient resistance to counteract the torque exerted when a theft is attempted. Each groove can receive the catch in a locking position. The shaft has at least two grooves (10).