Abstract: A plurality of finishing mills for finish rolling a rolled material are located in a row to configure a finishing mill group. First to third surface coolers for cooling surfaces of the rolled material are located on an entry side of each of first, second and third finishing mills of the finishing mill group, and the amount of cooling water jetted at the rolled material by each surface cooler under a command of a controller is set at 4,000 liters/min.multidot.m.sup.2, whereby the thickness of scale is restricted to 5 .mu.m or less.

Abstract: A plurality of finishing mills for finish rolling a rolled material are arranged in a row to construct a finishing mill group, 1st to 3rd surface coolers for cooling the surfaces of the rolled material are provided on the entrance side of the 1st to 3rd finishing mills of the fishing mill group, and the range of cooling of the rolled material by the surface coolers are set to be a range of 0.3 to 1.5 m toward the upstream side from a position separated by 1.5 m or less from the center of the work rolls of each of the finishing mills toward the entrance side of each of the finishing mills.

Abstract: A plurality of finishing mills for finish rolling a rolled material are arranged in a row to form a finishing mill group. A scale breaker is provided at an entry side of the finishing mill group, a glass coating material application device for jetting molten glass to upper and lower surfaces of the rolled material to form a molten glass film is located at a delivery side of the scale breaker, and a molten glass film removing device for removing the molten glass film formed on the upper and lower surfaces of the rolled material is located at the delivery side of the finishing mill group.