What Are Control Arms Really Made Of?

1.Stamped Steel Control Arms

   The oldest versions of control arms were most commonly made from stamped steel because it was cheap, fast, and easy. This style of control arm often held coil springs in place on full framed cars, and was also an attachment point for shocks and sway bars. Their major weakness is rust. When stamped steel control arms live in a wet environment, they are nearly guaranteed to deteriorate from rust. Once the rust takes over, replacing the bushings and ball joints becomes quite a challenge, and sometimes impossible without damaging the control arm. Luckily, these control arms are usually the most inexpensive to replace.

2.Cast Iron Control Arms

   Cast Iron control arms are very popular on modern vehicles, especially trucks and SUVs. When used in front suspensions, they are often wishbone shaped, with bushings on the inside and a ball joint on the outside. They are extremely strong and can withstand harsh environments better than the stamped steel control arms. If you drive a truck with independent front suspension, take a peek under the front of it. You likely have cast iron control arms.

3.Cast Aluminum Control Arms

   Over the years, many control arms have evolved from their humble stamped steel beginnings to elaborate cast aluminum pieces that are stronger and lighter than ever before. Being cast aluminum, they don't corrode quite like the steel control arms do, but since aluminum is a softer metal, they do bend and crack when things go wrong. This means that simple fender-benders or pot holes can potentially damage them, throwing the alignment way off.