PURPOSE: To prevent the generation of bend when an asymmetric H--shaped steel is rolled by rolling it while independently adjusting the rotational speed of right and left vertical rolls.

CONSTITUTION: A brake roll 9 is freely rotatably arranged in the back of the vertical roll 8 and in a housing 10. A brake 11 is brought into contact with the shaft part of the brake roll 9 and slip between the vertical roll 8 and the brake roll 9 is prevented by pressurizing force of a cylinder 13 for adjusting bearing position against their bearings 12. Braking force of the brake 11 is adjusted by controlling the extension of the rod of a brake operating cylinder 15. Consequently, the rotational speed of the nondriven vertical roll 8 accompanying rolling can be adjusted. As the 2nd embodiment, it is possible to prevent the generation of bend by independently driving each of the right and left vertical rolls with motors and independently adjusting output of the motors.