Abrasive materials – most commonly used synthetic abrasive in manufacturing Which of the following is the most commonly used synthetic abrasive for general grinding applications?

Introduction / Context:
Abrasives are critical in machining and finishing operations. In building-services workshops and general manufacturing, the “workhorse” synthetic abrasive used in grinding wheels and coated abrasives must combine availability, cost-effectiveness, and broad applicability. This question asks you to identify the synthetic abrasive most commonly used across general applications.

Given Data / Assumptions:

• We focus on general-purpose grinding of steels and common metals.
• The options include major synthetic abrasives used industrially.
• “Most commonly used” refers to widespread, everyday adoption rather than specialized niches.

Concept / Approach:

Aluminium oxide (Al2O3) is the dominant synthetic abrasive for grinding ferrous alloys due to its toughness, cost, and versatility. Silicon carbide (SiC) is harder but more brittle and excels on non-ferrous metals, cast iron, and non-metals. Boron carbide and CBN are specialized, high-performance abrasives used where extreme hardness or thermal stability is required but are not the day-to-day standard in most shops.

Step-by-Step Solution:

Verification / Alternative check:

Industrial catalogs and machining texts list alumina-bonded wheels as the standard for general steel grinding, with SiC and superabrasives reserved for specific materials or precision demands.

Why Other Options Are Wrong:

Silicon carbide (SiC): Common but less universal; more brittle and targeted uses.

Boron carbide (B4C): Very hard but expensive; used in specialized lapping and armor applications.

CBN: Superabrasive for hardened steels; high cost and specialized equipment.

Common Pitfalls:

Assuming “hardest” equals “most common”; ignoring cost and wheel toughness; overlooking the difference between ferrous and non-ferrous grinding behavior.

Final Answer:

Aluminium oxide (Al2O3, alumina/alundum)