Grit Size — Industry Glossary Entry

Grit Size is the nominal abrasive particle size of a grinding wheel, measured by the number of openings per linear inch in a sieve that the particles just pass through. A 60-grit wheel has coarser particles than a 120-grit wheel.

Typical grit sizes for blade grinding

• Roughing: 36–60 grit (aluminium-oxide, for shear blades and thick slitters)
• General re-grind: 60–80 grit (CBN or aluminium-oxide)
• Finishing: 100–120 grit (CBN)
• Hone restoration: 200–400 grit (felt wheel with diamond paste)

Coarser vs finer

• Coarser grit: faster stock removal, rougher surface, more heat input
• Finer grit: slower stock removal, finer surface, less heat input
• Too fine on a high-stock job: the wheel loads and burns the workpiece
• Too coarse on a precision finish: leaves grind marks and requires extra passes

See also.