PURPOSE: To reduce the number of motors and reduce capacity by driving the high speed rolls of upstream side stands and the low speed rolls of the adjoining downstream side stands at the same peripheral speed by common motors.

CONSTITUTION: The slab S coiled on a reel W1 is rolled by rolling mills of the 1st stand ST1, 2nd stand ST2... and is taken up on a reel W2. The lower roll R12 of the 1st stand ST1 and the upper roll R21 of the second stand ST2 are driven commonly by one unit of motor M1. Thence, the lower roll R22 of the 2nd stand ST2 and the upper roll R31 of the 3rd stand ST3 are driven commonly by one unit of motor M2. The rest are driven in similar combinations by respective motors M3 thru M4. In the stands ST1, ST5 on both sides, each motor drives only one roll. Since these eliminate the need for providing drive motors individually to the upper and lower rolls, the number of motors is considerably reduced and power source can be of a small capacity.