In combination with a roll (10 or 11) of a cold rolling mill for thin gage metal strip, an installation for directing a liquid against said roll, said installation comprising a plurality of elongated nozzle beams (15, 16, 17) that are parallel to said roll and to each other, at least one (15, 16) of said beams being stationary, each of said beams having a plurality of spray nozzles (18) arranged along the length thereof, said nozzles being directed at said roll to spray a liquid against the roll, detector means (3, 4) for detecting tensile stresses in a plurality of zones of a said strip across the width of the strip, and means (19) responsive to said detector means for moving one (17) of said beams lengthwise parallel to said roll and relative to said at least one stationary (15, 16) beam thereby to provide formation of narrowly limited cooling zones on the rolls over the roll width, said cooling zones corresponding to the strip zones detected by said detector means, thereby to eliminate by means of regulation, with maximum accuracy, any undesirable deviations in strip tensile strength in the rolled strip within specific areas.