The results of the study to determine the nature of the transformation of the defect «fin», which occurs in the case of a more intense deformation mode at the last stage of rolling in the reversing two-high stand, in the surface defects of metal products are presented. The marked increase, in this case, the number of surface defects in the form of hairline cracks and localization of the nature of their arrangement on the surface - two of the strips located diametrically on the perimeter and is formed from «fin».