The article describes the penetrant tests carried out on X5CrNi18-10 high-alloy steel provided with artificial discontinuities, i.e. pores (drilled openings). The tests involved the measurements of indication sizes depending on the time of development and various diameters and depths of openings. The correlations determined enable estimating the depth of pores in welded products made of high-alloy steels. The information obtained should enable decision-making concerning the acceptance of a product for operation or the necessity of repairing it. The tests also involved the determination of an optimum indication development time for high-alloy steels. The article is the continuation of the research works published in editions nos. 4/2012 and 4/2014 of this magazine.