Steel is best cut with the abrasive

• A. Aluminum oxide
• B. Silicon carbide
• C. Diamond
• D. Boron nitride

Answer: (A)

When choosing an abrasive for grinding steel, you want something that can cut effectively under heavy loading without breaking apart too easily. Aluminum oxide provides a good balance of hardness and toughness for ferrous metals, so it can maintain a sharp cutting edge and resist chipping while grinding steel. It’s durable, wears predictably, and is cost-effective, which is why it’s the standard choice for steel.

Silicon carbide is harder but more brittle, so it tends to fracture under the impact and heat of grinding steel, making it less durable for this metal. Diamond is extremely hard and can cut steel, but it’s expensive and not economical for typical steel grinding. Boron nitride is highly specialized and used for certain hard alloys and exotic materials, not the usual choice for everyday steel work.