PURPOSE: To make possible the sepn. of small-diameter rolling materials as well at a high speed without buckling by providing both frames on a driving side and work side with the pass line of the rolling materials as a boundary and driving simultaneously separators and pinch roller parts attached respectively thereto.

CONSTITUTION: A fine groove 5 is formed to a thin-walled part of the rolling material 3 formed with steel bar preform parts 7, 7 contracted at the part 4 by a roll stand 13 when said material enters a splitter 6. The one preform part 7 is pressed and bent upward and the other preform part 7 is presssed and bent downward when the material 3 emitted from the splitter 6 enters both separators 11, 11. The material is thus sheared and separated to two steel bars 10, 10 with the part 4 as the boundary. The two steel bars 10, 10 are respectively delivered from the driving side frame and the work side frame by both pinch roller parts 14, 14. Since the two separators 11, 11 and pinch roller parts 14, 14 are simultaneously driven in the above-mentioned manner, the rolling materials are rolled and separated at a high speed and the small- diameter rolling materials are separated without buckling.