Correct option is D
Grain size in materials like abrasive particles is classified based on the mesh size range. A grain size range between 90 and 220 is typically considered as fine grain. The classification of grain size is based on the number of grains present per unit area, typically represented by the
ASTM (American Society for Testing and Materials) grain size number.
Fine grains are used in applications requiring a smooth finish or in situations where finer abrasives are necessary to remove smaller amounts of material or to produce a finer surface texture.
· Very fine grain would have an even smaller range.
· Coarse grain would refer to larger particles with a lower mesh number.
· Normal grain would typically fall between coarse and fine grains in size.
