Aluminum Oxide: The Workhorse
Aluminum Oxide (Alox) is the most common abrasive grain. It's versatile, cost-effective, and works well on mild steel and cast iron. However, the grains tend to dull over time, requiring more pressure from the operator to keep grinding.
Zirconia Alumina: The Heavyweight
Zirconia Alumina (Zirc) is a synthetic blend that features a micro-crystalline structure. It is "self-sharpening"—as the grain wears, it fractures to expose sharp new cutting edges.
When to Use Which
- Use Alox for: General purpose grinding, mild steel, short-term projects, and budget-conscious operations.
- Use Zirc for: Heavy stock removal, high-tensile alloys, stainless steel, and high-volume production where labor costs and downtime outweigh the higher initial cost of the wheel.