PURPOSE: To perform one-direction reciprocating rolling by means of a minimum equipment by increasing stepwise the distance between slide rolls every time a material to be rolled is alternately passed from the reverse direction through the upper and lower slide rolls and rolling finally both side ends of the material by means of the right and left slide rolls respectively.

CONSTITUTION: A pair of right and left housings 12 are respectively equipped with a set of upper and lower bearing blocks 13, 14 which are vertically movable through jacks 15, a set of upper and lower guide shafts 17 which are parallel to each other and connected to driving sources and have both side ends fitted freely rotatably to the blocks 13, 14 respectively, slide rolls 19, 20 which are fitted slidably, each by two rolls, in the direction parallel to the longitudinal direction of the guide shafts 17 to hold a material 22 to be rolled under pressure from upper and lower sides as well as to rotate them with the shafts 17 in one body respectively, two upper and lower screw axes 23 which are connected to driving sources whose both side ends are supported freely rotatably and parallelly to the shafts 17 by bearing blocks 13, 14, and two upper and lower slide forks 24 which screw separately with the shafts 23 to hold the slide rolls 19, 20.