PRECISION ROLLING METHOD

PROBLEM TO BE SOLVED: To realize a dimensional tolerance of ±0.05 mm below in the final cross sectional dimension of a material to be rolled by using two-way rolling system rolling mill simple in constitution. SOLUTION: The rolling speed in the post-stage rolling mill 20 is made higher than the rolling speed in the preceding stage rolling mill 18, thereby applying tension to the material 10 to be rolled between both rolling mills 18 and 20. The material 10 is rolled by the preceding stage rolling mill 18 so that the reduction ratio of area is ≥16% and the dimensional tolerance of its diameter is ±0.1 mm. Then, the material 10 is rolled by the post-stage rolling mill 20 so that the reduction ratio of area is ≤10%. In this way, the product of the dimensional tolerance of ±0.05 mm below in the final cross sectional dimension is obtained. COPYRIGHT: (C)2005,JPO&NCIPI