| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing an anchor main body by which the manufacturing cost can be reduced. SOLUTION: A three-shaft cylindrical raw material W6 which has a medium diameter shaft part 30 in a tapered face 10a at the tip part of a large diameter shaft part 10 formed by die forging consisting of a die and a punch and punching of a bottom, and a small diameter shaft part 12 formed in a tapered face 30a at the tip part of the medium diameter shaft part 30, is formed from a cylindrical shape raw material W0 . The anchor main body is obtained by forming three slits extending in an axial direction from the tip part of the small diameter shaft part 12 which are formed by cutting the three-axis cylindrical raw material W6 . The three-shaft cylindrical raw material W6 of the preceding stage to form the slits is processed only by the die forging and bottom punching, and a thirling process by a drill is made unnecessary, thereby the manufacturing cost is reduced.
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