Carbon steel, on the other hand, has far lower chromium levels, and is instead a carbon-iron alloy with only a few other materials, if any, as part of its makeup. As a result, it can be referred to as ‘low-alloy’ steel. Both stainless steel and carbon steel feature this basic composition, but carbon steel can be defined by its carbon content. This is normally around 2-2.5%, however this often varies. Though susceptible to rust unlike stainless steel, carbon steel is often cheaper and has its own varying mechanical properties based on carbon content.