7 Machines operated by compressed air or other sources of energy, namely, electricity and hydraulics, for the working of forming sheet metal, cold and hot rolled structural elements, namely, studs and tracks, extruded profiles, machines used for mechanical joining, clinching, stitchfolding and riveting as well as hole making, and nibbling, namely, modular workheads, force units, power boosters; machine tools for the above tasks, namely, joining machines, clinching machines, stitchfolding machines, riveting machines, punching machines and nibbling machines; power tools for the above tasks, namely, power boosters, joining power tools, clinching power tools, stitchfolding power tools, riveting power tools, unching power tools and nibbling power tools; structural parts, spare and wear parts, namely, notably punches and dies therefor