Metal vs Steel: Are They the Same Thing?

The terms metal and steel are often used interchangeably, but do they really mean the same thing? Steel, a popular material for both construction and consumer products, certainly appears to be a tough metal. But appearances can be deceiving.

In fact, many people overlook the distinction between metal and steel, even though these terms are frequently used together. Steel is a common material in construction, and buildings referred to as "metal buildings" are often made from steel. This leads to the phrase "steel metal building" being associated with skyscrapers. But technically, the two terms are not synonymous and should not be used interchangeably.

So, what sets these often-confused terms apart? The answer lies in a few simple definitions.

A metal is a chemical element that is typically opaque, fusible, ductile, and has a shiny surface [source: Merriam-Webster]. These elements are the same ones you studied in high school chemistry when you learned about the periodic table. Common metals include titanium, copper, and nickel.

Steel, however, is an alloy made from iron with varying amounts of carbon (ranging from 0.5 to 1.5 percent) [source: Merriam-Webster]. Since steel is an alloy, it is technically not a pure metal but a variation of one. It’s made up of iron, a metal, but also contains carbon, a non-metal, in its structure.

To make steel, impurities such as silica, phosphorous, and sulfur are removed from iron ore before adding carbon. The primary advantage of steel over iron is its strength, which is why it's used in applications ranging from automobiles to the bridges they cross. Steel is also found in skyscrapers, firearms, ships, trains, and surgical instruments.