This International Standard specifies a micrographic method of determining the non-metallic inclusions in rolled or forged steel products having a reduction ratio of at least 3 using standard diagrams. This method is widely used to assess the suitability of a steel for a given use. However, since it is difficult to achieve reproducible results owing to the influence of the test operator, even with a large number of specimens, precautions should be taken when using the method. NOTE For certain types of steel (e.g. free cutting steels), the standardized diagrams described in this International Standard may not be applicable. This International Standard also provides for the determination of non-metallic inclusions by image analysis technologies (see Annex D).