Abstract: A girder includes at least one elongated profiled rod which is provided with at least one bearing surface extending longitudinally of the rod and centered on an imaginary longitudinal plane for supporting at least one associated engagement element during displacement of the latter longitudinally of the profiled rod. The profiled rod further includes two longitudinal webs extending along respective longitudinal central planes which enclose an angle with one another and intersect each other and the imaginary longitudinal plane of the bearing surface substantially in a common longitudinal axis of the profiled rod. The carrier further includes at least one girder body joined to at least one of the longitudinal webs at a transition region and extending along a common plane therewith at least at the transition region. The carrier body is advantageously constituted by a flat wall which includes at least one relatively thin-walled plate and reinforcing elements attached to the plate and reinforcing the same.