Selecting the right grit size is critical for achieving the desired surface finish. Coarse grits (16-60) are used for heavy grinding and rust removal, while fine grits (120-220+) are ideal for precision polishing and glass lapping. Ensure the purity of Aluminum Oxide (Al2O3) and Iron Oxide (Fe2O3) content aligns with your industry standards; for instance, high-purity emery is required for optical lens grinding to prevent scratching, whereas lower purity may suffice for anti-slip flooring aggregates.