The invention relates to a cluster mill having four columns 5, 6 connecting the lower part 1 and the upper part 2 for the sets of rolls 3, 4. Associated with each column 5, 6 is a lifting device 11, 12 enabling the lower part 1 and the upper part 2 to be moved wide apart. A hydraulic roll screw-down system independent thereof has an adjustable piston 16 which can be attached to the column 5, 6 and between which and the bottom of its cylinder casing 17 borne by the upper part 2 the necessary roll force can be built up. Due to the adjustable piston 16, for any required roll gap the cylinder space in which the pressure for the roll force is built up has a low height.