According to NEC® 300.6(A), which of the following metals are considered to be "ferrous"?

Ferrous metals are defined as metals that contain iron. The National Electrical Code (NEC) specifies materials based on their properties, which is important for electrical installations, particularly when discussing corrosion resistance and magnetic properties.

In this case, carbon steel is classified as a ferrous metal because it is primarily composed of iron, with carbon added to improve its strength and other mechanical properties. The presence of iron is what differentiates ferrous metals from non-ferrous metals.

On the other hand, stainless steel, while it does contain iron, is considered an alloy that includes chromium, which provides increased corrosion resistance. However, it is generally not categorized as a "ferrous" metal in the same context as carbon steel when discussing corrosion performance in the NEC. Copper and aluminum are both non-ferrous metals, as they do not contain iron, distinguishing them from the ferrous category.

Understanding the classification of metals based on their iron content is essential for determining their suitability for various electrical applications, especially in environments that may lead to corrosion or require specific magnetic properties.