GRAIN (Abrasive)

In the context of abrasives, grain refers to the size of the abrasive particles and, by extension, their density on a surface or within a given volume. This characteristic Applied marker to all types of abrasives — papers, cloths, pastes or solutions — regardless of the nature of the abrasive material: emery, corundum, carbide of Silicon, Diamond, etc. Grain is generally expressed as an index: the higher the number, the finer the particles. A coarse grain removes material quickly but leaves a marked surface finish, whereas a fine grain works slowly and refines the Polished. In watchmaking and finishing trades, work proceeds in successive passes, from the coarsest grain to the finest, in order to progressively erase the marks left by the previous step. The choice and sequence of grains determine the final quality of a polishing, a satin finish or a softening.