Metal has always played a major role in human society for many thousands of years. In fact, some periods of pre-history are named after the most common metals used and mined in that time, such as the Copper Age, Bronze Age, and Iron Age. Silver mining dates back in present-day Turkey for several thousand years, and precious metals have been valued from antiquity to today. Meanwhile, work-oriented metals such as steel, iron, copper, aluminum, and tin have long since been a valuable commodity, being used to build nearly any sort of tool or weapon imaginable. Both in history and today, such metals are a major presence in trade routes, and now in the 21st century, the global steel trade is still going strong. Thin steel sheets may be rolled and exported all over the globe, and stainless steel is useful just about everywhere. But thin steel sheets are not alone; thin metal strips may also be made of brass and copper, or combined metals for specialized work.

On Steel

Steel is not a catch-all metal, but it may come close. This metal is refined iron, and has been used since the Middle Ages, if not earlier, to make knight armor and swords. Starting with the Industrial Revolution, steel was being produced in vast quantities in factories and refineries, such as Andrew Carnegie’s steel mills in the U.S. Steel transformed how humanity made buildings, and this metal made skyscrapers possible. Many other items, ranging from automobiles to household appliances and even weapons of war, make good use of steel, and it all starts with humble thin steel sheets.

This makes for a robust economy of thin steel sheets around the world. In 2016, the United States alone employed some 138,900 sheet metal workers, and the metal fabrication industry may grow 9% from 2016 to 2026, according to the U.S. Bureau of Labor Statistics. This may add some 12,000 jobs to that sector in taht time frame, and this matches a global trend of thin steel sheet production growth. This metal is also known for its robust capacity to be recycled; around 90% of all steel is recycled, and around 40% of steel production today is done with recycled materials. The United States, China, Germany, Canada, and Japan are some of the world’s top producers and users of steel, and the United States stands as Canada’s single biggest customer for Canadian-produced steel. It may not be a coincidence that the U.S., Germany, China, and Japan are also among the world’s top car-producing nations.

Sheets of Steel

Once metals are melted down, purified, and forged into thin steel sheets, there are some more options to pursued. All thin steel sheets are hot rolled; that is, they are sent through pressurized rollers in a room at a very high temperature. In some cases, rolls of steel sheets are exported like this, known as hot rolled steel. This metal is useful for industries that do not need precise dimensions in the metal, such as production of train rails. Hot rolled steel is somewhat imprecise in its dimensions.

In other cases, hot rolled steel will be rolled again, this time at room temperature, or “cold rolled.” This metal is precise in its dimensions and has a tough, glossy surface. Such metal is useful for producing cars and household appliances and the like, though care must be taken when packaging and transporting it.

Alloys

Steel is widely useful, but it cannot do everything. Thus, composite metals, or alloys, are also used. Such alloys may contain steel, copper, brass, nickel, titanium, and more, and the exact compositions may vary based on the intended use. Such alloys may be built with extremes of high or low temperatures, pressure, or corrosion or salinity in mind. Flexible tubes of metal, known as metal bellows, may be made of an alloy that can endure extreme heat and pressure inside, and flex without rupturing or melting apart. Meanwhile, chemical plants may have valves, tanks, pipes, and pumps made of alloys that can endure constant exposure to strong acids or bases. Underwater pipes may be made out of alloys that can withstand constant exposure to sat water, where other metals such as steel might corrode and develop leaks over time.