Industrial ovens, namely, hardening, tempering, annealing and normalizing ovens for industrial use and furnaces, none of the foregoing for food and beverages; cooling plants and apparatus, namely, cooling plants and apparatus for roller hearth furnaces, batch furnaces and walking beam furnaces for industrial use; furnaces, apparatus and installations, namely, continuous roller hearth furnaces, batch furnaces and walking beam furnaces, all for heat treatment of metals; electric heat-treating f...