Abstract: In a sizing rolling method carried out by installing at least 3 sets of 4-roll rolling mills in series, a central angle &thgr;1 of the perfect circle forming section of each rolling roll in a first path is set to less than 15°. The central angle &thgr;3 is set to at least 45° in a third path and the central angle &thgr;2 is set to at least 30° in a second path B. The groove of each rolling roll is arranged such that each escape section is composed of the tangential line of an arc formed by the perfect circle forming section. A roller guide having four guide rollers is installed on the inlet side of the second path and the free surface of a workpiece is held and guided by the guide rollers. An angle &agr; of the V-shaped groove of each guide roller is set similar to the angle (90°+&thgr;1) between straight lines forming the escape section of the adjacent rolling rolls in the first path. With this technology, even if a wire has a diameter of 7.

Abstract: The present invention relates to a roll stand for bar and wire rod rolling mill, capable of being applied to various sizes of bars and wire rods by a small number of housing block sets, permitting maintenance work therefor to be carried out easily, and having characteristics in the housing thereof. The roll stand for bar and wire rod rolling mill according to the present invention is characterized in that the housing is divided into two, i.e. a roll block and a driving block by a plane including a position in which a driving gear and a driven gear are meshed with each other or a position in the vicinity of this position, whereby the number of housing block sets to be prepared is reduced. This enables the housing manufacturing cost to be lowered, and the replacement of a roll to be carried out efficiently.

Abstract: A high-speed rolling apparatus for bars includes a finishing mill and an associated first mill motor and a sizing mill and an associated second mill motor downstream of the finishing mill. The first mill motor power (Wf) and second mill motor power (Ws) satisfy the expression: Wf/Ws≧5. The apparatus provides simple and highly accurate control of the tension that is applied to the bars between the finishing mill and the sizing mill.

Abstract: A method of adjusting a roll position in a bar steel rolling mill includes using portions of a roll caliber, that are located at approximately symmetrical positions with respect to a rolling reduction direction, as sensing positions, and calculating the sum of, and the difference between, the areas located between a reference profile and an actually measured profile at the sensing positions.

Abstract: The present invention provides a rolling method and apparatus for manufacturing concrete-reinforcing steel bars, wherein the invention provides for obtaining various concrete-reinforcing steel bars satisfying the required specifications for knot height while using the same finishing rolls even if the diameters of the final product steel bars are different. According to the present invention, two pairs of rolls (total of four rolls) each having a roll caliber and one or more knotting round calibers are used for the final finishing pass, and the two pairs of rolls are arranged to exert rolling pressures in two orthogonal directions on a raw material S.