The metal smelting and refining industry processes metal ores and scrap metal to obtain pure metals. The metal working industries process metals in order to manufacture machine components, machinery, instruments and tools which are needed by other industries as well as by the other different sectors of the economy. Various types of metals and alloys are used as starting materials, including rolled stock (bars, strips, light sections, sheets or tubes) and drawn stock (bars, light sections, tubes or wire). Basic metal processing techniques include:
- smelting and refining of metal ores and scrap
- casting molten metals into a given shape (foundry)
- hammering or pressing metals into the shape of a die (hot or cold forging)
- welding and cutting sheet metal
- sintering (compressing and heating materials in powder form, including one or more metals)
- shaping metals on a lathe.
A wide variety of techniques are used to finish metals, including grinding and polishing, abrasive blasting and many surface finishing and coating techniques (electroplating, galvanizing, heat treatment, anodizing, powder coating and so forth).