Diamond Grit Size Explained: A No-Nonsense Guide for Tile Factory Owners

You see numbers like 36, 200, 800, 1500, and 3000 on polishing pads. Most buyers know that higher numbers mean finer polish. But very few understand how to choose the right progression between these numbers. Getting this wrong costs you time and money.

Coarse grits from 36 to 120 are for shaping and flattening.

These grits remove material fast. Use them when your tiles have uneven surfaces, saw marks, or heavy glue residue. Do not skip this step. If you move to fine grits without fully flattening the surface, every deeper scratch will remain visible under your final gloss. A good rule is to stop coarse grinding when the surface feels uniformly smooth to your fingernail.

Medium grits from 150 to 600 are for scratch refinement.

This is where most factories try to save time and fail. Medium grits remove the scratches left by coarse pads. You need to stay on this step until the surface has a consistent matte finish with no visible lines. Rushing through medium grits is the number one cause of the orange peel effect.

Fine grits from 800 to 3000 are for gloss building.

These grits do not remove material. They only polish what the medium grits have prepared. If your medium grit work was incomplete, fine grits will make the problem more visible, not less. Only move to fine grits when your matte finish is perfectly uniform.

The golden rule of grit progression.

Never skip more than two grit levels between steps. Going from 120 to 800 leaves scratches that 800 cannot remove. The correct path is 120, 240, 400, 800, 1500, 3000. Add more steps for mirror finishes. Remove steps only for matte finishes.

Need a grit chart for your specific tile type?

Send us your tile hardness and desired gloss level. We will provide a step-by-step progression table customized to your production line.