| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a serration molding method of molding a serration without occurring swelling and cracking in a shaft part at a position axially leaving a small space relative to a head part. <P>SOLUTION: A reduction in cross-sectional surface of a processed part 30 in welding process is set within a range from at least 0% to not more than 1.5%, and each of serration molding parts 41, 41 which are formed on a serration molding die 40 to mold a serration 13 on the processed part 30 is formed into a shape that an inlet part 41a extends outward in a radial direction of the serration molding die 40 and inward in a circumferential direction of the serration molding part 41 as it goes upward. <P>COPYRIGHT: (C)2013,JPO&INPIT |
