This International Standard specifies a method for determining or checking the grain size of superabrasives (diamond or cubic boron nitride) as used for the manufacture of industrial products, such as grinding wheels and saws. It is applicable to grain size designations as defined in Tables 2 and 3. This International Standard describes the grain size designations, the size limits, the sieves for use in determining them and the procedure to be adopted for checking the grain size exclusive of any coating.