PURPOSE: To handle rods having different diameters by providing adjustability for the gap of a slit formed by a receipt plate and a pressing plate in accordance with the size of the rod handled.

CONSTITUTION: A framing 11 is formed from two or more frames, upper and lower, which pinch a pressing plate 6 and receipt plate 6 in the axial direction of a rod 2, and a piston rod 23 of adjusting cylinders 24 for a slit 7 is fixed to frame 11B on the receipt plate side, wherein this frame 11B is used as the stationary side while the pressing plate 6 side frame 11A is as the moving side, and the slit adjusting cylinders 24 are secured to the moving side frame 11A. These cylinders 24 are arranged in front of and behind the framing 11 both in the overpart and underpart and are adapted to make synchronous operation. The cylinders 24 are operated in accordance with the size of the rod 2 to move the frame 11A relative to the frame 11B, and the pressing plate 6 is moved fore and aft relative to the receipt plate 8. The gap 7 of the slit is thus adjusted.