Which material is ferrous, tough, ductile and malleable with good tensile strength, used for nuts, bolts and car body panels?

• A. Cast iron
• B. Mild Steel
• C. High Carbon Steel
• D. Aluminium

Answer: (B)

Mild steel offers a balance of properties that fit all parts of the description. It’s ferrous (iron-based) with a low carbon content, which gives it a good mix of toughness, ductility and malleability while still providing solid tensile strength. That means it can be shaped into car body panels without cracking, and it can be formed and threaded to make nuts and bolts that won’t fail under load. Cast iron is too brittle for fasteners and panels, high carbon steel is stronger but much less ductile, and aluminium isn’t ferrous at all. So mild steel best matches the combination of being ferrous, tough, ductile and malleable with good tensile strength.