Nonmetallic inclusions (NMI) of wrought steel differ in size, shape, concentration, distribution and chemical composition. Several methods are used to characterize the intermetallic phases. In particular, microscopic methods allow to detect and rate the inclusion content according to the type (sulfide, alumina, silicate or globular oxide) and number of the inclusions by means of comparison to representative photomicrographs and standard reference charts depicting a series of typical inclusion configurations.