Which statement about ferrous metals is true?

Which statement about ferrous metals is true?

• A. They are always magnetic.
• B. They are non-magnetic in all cases.
• C. They are corrosion-resistant.
• D. They contain iron.

Answer: (D)

Ferrous metals are defined by containing iron. That iron content is what sets them apart from non-ferrous metals and includes steels, cast irons, and wrought irons. Because they contain iron, many ferrous metals are attracted to magnets, but magnetic behavior isn’t universal—some ferritic or austenitic stainless steels are weakly magnetic or effectively non-magnetic, so saying they are magnetic in all cases isn’t correct. Likewise, corrosion resistance isn’t guaranteed for ferrous metals; many rust easily unless alloyed or protected. Stainless steel is an exception among ferrous metals, offering corrosion resistance due to chromium, but that’s not a property of all ferrous metals. The defining truth remains that they contain iron.

Ferrous metals are defined by containing iron. That iron content is what sets them apart from non-ferrous metals and includes steels, cast irons, and wrought irons. Because they contain iron, many ferrous metals are attracted to magnets, but magnetic behavior isn’t universal—some ferritic or austenitic stainless steels are weakly magnetic or effectively non-magnetic, so saying they are magnetic in all cases isn’t correct. Likewise, corrosion resistance isn’t guaranteed for ferrous metals; many rust easily unless alloyed or protected. Stainless steel is an exception among ferrous metals, offering corrosion resistance due to chromium, but that’s not a property of all ferrous metals. The defining truth remains that they contain iron.