What feature distinguishes stainless steel from regular steel?

The distinguishing feature of stainless steel is its resistance to corrosion, which sets it apart from regular steel. This corrosion resistance is primarily due to the presence of chromium in stainless steel, typically comprising at least 10.5% of the alloy. Chromium forms a thin, passive layer of chromium oxide on the surface of the steel, which protects it from rust and oxidation when exposed to moisture and various chemicals.

Regular steel, on the other hand, lacks this protective layer and is more susceptible to corrosion when exposed to environmental conditions. This makes stainless steel the preferred choice for applications that require durability and longevity in environments where corrosion could be a significant issue, such as in kitchens, medical equipment, and outdoor structures.

Moreover, while carbon content, weight, and machinability play important roles in the characteristics of various steels, they do not define the unique properties of stainless steel in relation to corrosion resistance.