An external corona shielding for a conductor bar of an electric machine, a main insulating layer sheath on the conductor bar. The shielding has a first ply, which sheaths the main insulating layer, and a second ply, which sheaths the first ply. Each ply is a conductive, impregnatable layer with a sliding layer, wherein the sliding layers of the two plies (20, 21) face one another. Each sliding layer has at least one cutout, wherein the two conductive layers are connected to one another through these cutouts with the aid of a permanently elastic, electrically conductive connection.