What Is the Metals Industry?

The metals industry is the sector of manufacturing and processing concerned with extracting metals from ore and scrap, refining crude metals, and converting them into semi-finished and finished metal products for sale to downstream fabricators and end users. It encompasses primary production facilities that smelt and refine metal directly from mined concentrates, secondary production operations that recover and reprocess scrap and recycled material, and downstream mills and foundries that shape metal into plate, sheet, rod, castings, and other standard product forms. The sector is a foundational input to virtually all branches of manufacturing, including construction, transportation, energy, and electronics.

The industry's scale is substantial. Iron and steel production accounts for approximately 95 percent of total global metal output by mass, with aluminum, copper, zinc, and nickel constituting the largest non-ferrous segments. According to OSHA's classification of Major Group 33, the primary metal industries include establishments engaged in smelting and refining ferrous and non-ferrous metals from ore, pig, and scrap; rolling, drawing, and alloying; and manufacturing basic metal products including nails, wire, pipe, and castings.

Smelting and Refining

Smelting is the high-temperature reduction of metal oxide or sulfide concentrates to produce crude metal. In iron and steel production, iron ore is reduced in a blast furnace with coke and limestone, yielding molten pig iron that is subsequently refined in a basic oxygen furnace or an electric arc furnace to produce steel with controlled carbon and alloying element content. Non-ferrous metals use different routes: aluminum is produced by the Hall-Heroult electrolytic reduction of alumina in molten cryolite, consuming large quantities of electrical energy; copper is smelted from sulfide concentrates in flash smelters, then electrorefined to 99.99 percent purity. Secondary smelting remelts and refines scrap metal, consuming far less energy than primary production and diverting material from landfills.

The International Labour Organization's encyclopedia on smelting and refining operations describes in detail the occupational and process engineering aspects of pyrometallurgical refining across ferrous and non-ferrous operations, including converter smelting, fire refining, and electrolytic refining.

Metal Products Manufacturing

Once refined, metals are converted into standard product forms by a series of mechanical working operations. Rolling mills reduce cast slabs and billets to plate, sheet, strip, bar, and structural sections through a sequence of hot and cold rolling passes that simultaneously shape the metal and refine its grain structure. Extrusion presses force heated billets through shaped dies to produce complex cross-section profiles in aluminum, copper, and titanium. Foundries pour molten metal into sand, permanent metal, or investment molds to produce castings with intricate internal geometry that would be impractical to machine from solid stock.

Wire drawing is a continuous process in which rod is pulled through a series of progressively smaller dies, reducing diameter while increasing strength through work hardening. Wire and cable products from copper and aluminum are direct outputs consumed by the electrical and telecommunications industries. Tube and pipe mills produce hollow sections used in construction, oil and gas, and chemical processing by piercing, rolling, or welding flat strip.

Recycling and Circular Economy

Secondary metal production from scrap has grown substantially as environmental regulation and energy costs have made primary smelting less competitive relative to recycling. Electric arc furnace steelmaking, which can operate entirely on scrap feedstock, now accounts for roughly 30 percent of global steel output. Aluminum recycling requires only about 5 percent of the energy of primary Hall-Heroult production. The US Bureau of Labor Statistics primary metal manufacturing profile tracks employment, output, and productivity trends across both primary and secondary sectors of the industry.

Applications

The metals industry supplies material inputs to a broad range of downstream sectors, including:

• Construction with structural steel, aluminum extrusions, and copper plumbing
• Automotive and aerospace manufacturing using sheet, extrusions, and castings
• Electrical power systems consuming copper conductors and silicon steel cores
• Electronics packaging using high-purity copper, aluminum, and specialty alloys
• Consumer goods including appliances, packaging, and household hardware