The invention is relative to opening devices for spinning machines, especially open-end spinning machines, that are provided with clothing wires or rings for separating fibers of a supplied sliver. The opening device is characterized in that the clothing wires are pre-bent in accordance with the geometry of a carrier ring, or the clothing rings have the desired geometry of the finished part, and that the particular workpiece surfaces have an at least two-coating construction in which an outer coating is a hard-substance coating. The hard-substance coating consists entirely or partially of especially hard hard-substance components and rests on a substrate layer located underneath it.