grit size definition
Grit size refers to the size of the particles of abrading materials embedded in the sandpaper. Several different standards have been established for grit size. These standards establish not only the average grit size, but also the allowable variation from the average.andpaper comes in a number of different shapes and sizes: 1  sheet: usually 9 by 11 inches, but other sizes may be available. 2  belt: usually cloth backed, comes in different sizes to fit different belt sanders.