Which metal is ferrous, rusts, brittle and commonly used for manhole covers and machine vices?

Which metal is ferrous, rusts, brittle and commonly used for manhole covers and machine vices?

• A. Cast iron
• B. Stainless steel
• C. High Speed steel
• D. Mild steel

Answer: (A)

Cast iron fits this description because it is iron-based (ferrous) and will rust when exposed to moisture. Its structure makes it brittle rather than ductile, so it can crack under tension but it can be cast into heavy, rigid shapes. These properties, along with its low cost and good wear resistance, make it ideal for large cast components like manhole covers and for vices where a hard, wear-resistant, stable base or jaw is needed. Stainless steel would resist rust, so it wouldn’t rust; high speed steel is a cutting-tool alloy not used for large cast parts; mild steel is more ductile and prone to bending and wear, not as well suited for those specific heavy cast applications. Cast iron is the best match.

Cast iron fits this description because it is iron-based (ferrous) and will rust when exposed to moisture. Its structure makes it brittle rather than ductile, so it can crack under tension but it can be cast into heavy, rigid shapes. These properties, along with its low cost and good wear resistance, make it ideal for large cast components like manhole covers and for vices where a hard, wear-resistant, stable base or jaw is needed. Stainless steel would resist rust, so it wouldn’t rust; high speed steel is a cutting-tool alloy not used for large cast parts; mild steel is more ductile and prone to bending and wear, not as well suited for those specific heavy cast applications. Cast iron is the best match.