Coating, engraving, cold and heat treating and allied activities

North American Industry Classification System code (NAICS): 3328

This industry group comprises establishments primarily engaged in coating, engraving, heat treating and similarly processing metal. These activities often involve heating the metal, and the purpose is often to harden it. In general, the hardening of metal is included. Other activities of this industry group include tempering, brazing, plating (including electroplating and re-chroming), polishing, sand-blasting and colouring metal and metal products. Establishments that perform these processes on other materials, such as plastics, in addition to metals, as well as establishments primarily engaged in plating with precious metal for the trade are included.