| 摘要 |
PROBLEM TO BE SOLVED: To improve wear resistance for the surface of a needle kind, to substantially improve durability, to provide the sewing machine needle of high quality provided with buckling rigidity sufficient as the needle kind for hardly causing breakage accidents, to easily manufacture the needle kind, to improve productivity and to manufacture it at a low cost. SOLUTION: The surface of a needle trunk part 3 from a handle part 1 through a tapered part 2 to a needle tip 4 is shot-peening processed by a shot provided with hardness at least equal to or more than a metallic needle material and a surface processing layer 12 is provided on a shot-peening processed outer peripheral surface 11. Further, by turning the surface of the surface processing layer 12 to a shot-peening processed outermost peripheral surface 13 by the shot provided with the hardness at least equal to or more than the metallic needle material, this needle kind such as the sewing machine needle of the high quality provided with the sufficient buckling rigidity for hardly causing the breakage accidents is attained. |
