3541 Machine Tools, Metal Cutting Types Establishments primarily engaged in manufacturing metal cutting type machine tools, not supported in the hands of an operator when in use, that shape metal by cutting or use of electrical techniques; the rebuilding of such machine tools, and the manufacture of replacement parts for them. Also included in this industry are metalworking machine tools designed primarily for home workshops. Establishments primarily engaged in the manufacture of electric and gas welding and soldering equipment are classified in industry 3548, and those manufacturing portable power-driven handtools are classified in industry 3546.