3D printers; 3D printing apparatus; machine plasma arc torches; machine tools for working metals; machines for metal processing; machines for shaping metal; metal processing machines; metal welding machines [electric]; metal welding machines [gas]; metal working machines; metalworking machines; metal-working machines; welding apparatus (electric -); welding apparatus (electric arc -); welding apparatus, gas-operated; welding machines; welding machines, electric; welding machines (gas-)