The rolling mill for mechanical descaling of hot rolled steel is constructed according to the slidable roll process with reducing rolls so that a unform operation with different and/or changing shape steel strips can obtained. This is attained when the rolling mill has at least two rolls slidable in opposite directions whose body surfaces are constructed with S-shape contours positioned inversely to each other so that these contours compliment each other flawlessly in one certain axial relative position. When sliding the rolls in opposite directions in one case the contour is decreased in the center region of the steel strip and when slid in the opposite directions in the other case the contour is increased in the center region. Thus the rolls can be adjusted to fit a gently convex steel strip profile by axially sliding the rolls in opposite directions as also rolled strips with a thickness centrally reduced in comparison to that of the edge regions can by appropriate sliding of the rolls opposite each other.