Topic summary
Grit size
Extracted from the Wikipedia article Sandpaper.
Grit sizes
Grit size is the size of the abrasive particles attached to the sandpaper. Sandpaper comes in a variety of grit sizes, ranging from very coarse (≈2 mm) to ultrafine (<1 μm). Coarser grit materials simplify sanding of hard surfaces, but also make it easier to accidentally damage fine details.