Which of the following is a non-ferrous metal?

• A. Cast Iron
• B. Aluminium
• C. Stainless Steel
• D. Mild Steel

Answer: (B)

Non-ferrous metals are metals that do not contain iron as their main constituent. Aluminium fits this category because it is not an iron alloy, so it remains non-ferrous. The other options are all iron-based alloys: cast iron, mild steel, and stainless steel are ferrous because they rely on iron as their primary component. Stainless steel is iron with chromium and other elements, but it’s still iron-based. Cast iron and mild steel are also iron-carbon alloys. Aluminium’s light weight, good corrosion resistance, and conductivity illustrate why it’s a common non-ferrous metal.