PURPOSE: To bear a large bender force and to enlarge a shape controlling range by dividing a roll chock of work roll into an inside roll chock and an outside one.

CONSTITUTION: The inner rings of a No.1 roller bearing 2 and a No.2 roller bearing 3 mounted on an inside roll chock 5 are constructed to be free from a work roll 1. Because only a radial load (mainly a bender load) is burdened on these roller bearings 2, 3, comparatively thin-type bearings can be used, and the roll-neck diam. of the work roll 1 can be made larger by an amount corresponding to the amount saved by using said bearings. The thickness of a No.3 roller bearing 4 is increased by providing a step to the journal part of roll 1; then a bearing having a larger loading capacity can be selected, which is durable for a bender load and a thrust load in the same degree as compared with the durabilities of the No.1 and No.2 roller bearings 2 and 3.