As nonmetallic inclusions in steel get fewer and smaller, the use of SEM/EDS to rate them becomes more informative. Traditional metallography measures inclusion content by ASTM Standards E 45 and E 1122. A new standard, E 2142, addresses the need for compositional information and higher resolution, and it permits users to set up their own classifications based on size, shape, and chemistry. Chemical classifications can be defined to account for duplex and complex inclusions. When exploiting the resolution of the SEM, one must remember the magnification effect, whereby more inclusions are detected at higher magnification. For equal total field areas, when magnification was changed from 200X, to 400X, to 800X, the number of inclusions increased while their size decreased, as expected. Although it is necessary to account for SEM magnification, the ability to classify inclusions chemically is a powerful characterization tool to enhance, but not replace, traditional optical metallography.