| 摘要 |
PROBLEM TO BE SOLVED: To manufacture a die easily by getting rid of difference of diameter of medium fine shaft part irrespective of axial length of the shaft with respect to a medium fine shaft molding using a die for cross rolling. SOLUTION: A die is equipped with a slope shaped engaging part 21 expanding from a top end part with an angleβ2 of advancing direction and having a prescribed forming angle, and further equipped with an extending part 22 comprising a plane 221 gradually decreasing tits height from a top part 21p toward the rear end and a sloped plate 222 continuing to the engaging part 21 on both the sides, and furthermore, composing the whole of a nearly plane surface, the plane 221 of the extending part 22 is formed so that the central part is low with respect to both the sides in the width direction, according to an axial length of the medium fine shaft part in forming the medium fine shaft; thus a forming pressure against a round bar stock is adjusted.
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