It’s no secret that many various metals are involved in manufacturing auto parts. Less commonly known, though, is which specific metals are used the most and for what reasons. Whether it’s for mechanical strength, resistance to damage, weight, low costs or ease of manufacturing, there are particular metals and alloys that the industry has come to rely on.
Steel and Iron
Easy to work, inexpensive, readily available and reliably strong, steel is a staple in automobiles. The chassis and body panels of a vehicle, as well as many wheels, are frequently made of steel, not only for durability but also for flexibility—steel bends or dents under impact, absorbing kinetic energy well without breaking, which is a vital safety feature in cars and trucks. Some steel alloys have key traits besides mechanical strength that make them valuable; stainless steel, for instance, makes for corrosion-resistant bolts and exhaust pipes.
Iron is less common in modern models, usually outclassed by steel or other alloys. However, iron can be cast more readily than steel, making it useful for complex parts that need high dimensional stability.
Most people think of metal foil or cans when they think of aluminum, so it might surprise you to know that aluminum alloys can boast strength on par with steel. On top of that, aluminum is significantly lighter than steel, and surface treatments can make it corrosion resistant. Though working aluminum has historically been more expensive, modern advances in metalworking allow aluminum die castings to be used for a variety of auto parts, making its use more common nowadays. Still, economically speaking, aluminum remains a high-end material for many purposes.
Titanium is considered a premium metal in the automotive industry. While it’s prohibitively expensive to work with, limiting it to high-end models, it possesses an unparalleled strength-to-density ratio along with high stiffness, corrosion and oxidation resistance and consistent performance across a wide temperature range. Luxury sports cars make use of titanium to boost toughness and remain lightweight.
The prized materials in the automotive industry have changed over time as advances in technology-enabled more economic manufacturing. As metalworking practices continue to evolve, alloys that are costly now may see wider usage in the future.