| 摘要 |
PROBLEM TO BE SOLVED: To continuously form a pipe metallic tool from a solid blank with one set of a forming apparatus, to reduce a material cost and a manufacturing cost of the pipe metallic tool, to improve the quantity and to lighten the pipe metallic tool. SOLUTION: The solid blank 3 is forged to form a pipe body 6 having partitioned wall part in the inner part near the one end side. Successively, the partitioned wall is punched out to form a pipe body 7 having no partitioned wall. Further, the pipe body 7 having no partitioned wall is compressed so as to bulge toward outside from both end sides to form small diameter pipe parts at both end portions and thereafter, parallel with this formation, the expanding diameter state pipe part 41 is formed at the center portion in the length direction to form the pipe metallic tool W.
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