Aluminum and steel are among the most commonly used metals in the manufacturing industry. From airplane fuselage panels and automotive frames to  nuts, bolts and washers, there are a countless number of items made of these metals. While they share some similarities in terms of appearance, however, aluminum and steel are two very different metals with their own unique characteristics.

Cost

It’s a common assumption that aluminum is cheaper than steel. Because after all, wouldn’t soda cans be made of the cheapest metal possible for cost-savings benefits? Like all metals, the cost for steel and aluminum fluctuate depending on supply, demand and other economic factors. With that said, though, steel is typically cheaper (pound for pound) than its aluminum counterpart.

Rust and Corrosion

A key benefit of aluminum is its natural resistance to rust and corrosion. Unlike steel, aluminum is protected by a layer of aluminium oxide, which acts to protect the metal from exposure with air and oxygen — two elements that are needed for the oxidative effects of corrosion. The good news is that there are certain types of rust-resistant steel, known as stainless steel. They typically contain small concentrations of alloy metals like chromium to protect against corrosion.

 Strength

In terms of strength, steel is the undisputed winner. The vast majority of cars and trucks on the road feature steel frames for this very reason. It’s stronger and more durable than aluminum, making it the preferred choice in automotive and similar applications. However, Ford has begun to experiment with the use of aluminum in its F-150 frames. The automaker claims that aluminum’s lightweight properties make it ideal for use in frames, as it encourages greater fuel efficiency. It’s unclear whether or not these aluminum frames will take off, as steel remains the dominant metal in automobile manufacturing.

 Weight

Because it’s stronger and more durable than aluminum, steel also weighs more than its counterpart. Steel is essentially 250% times denser than aluminum, making it obviously heavier. And due to its high density/weight, it’s less likely to bend under force or heat.

These are just a few of the key differences between steel and aluminum. Of course, these two metals are not always interchangeable, meaning you cannot use steel in place of aluminum or vise-versa — not for all applications, at least.