| 摘要 |
PROBLEM TO BE SOLVED: To provide a seamless integrated metallic draw pipe, and its manufacturing method. SOLUTION: In the metallic draw pipe, a contracted pipe portion, an expanded pipe portion and a non-worked original pipe portion are continuously integrated in a seamless manner via a tapered portion through a plurality of drawing sets, and the metallic draw pipe comprises, from one end to the other, the contracted pipe portion, the tapered portion, the original pipe portion, the tapered portion, the contracted pipe portion, the tapered portion, and the expanded pipe portion. In the metallic draw pipe manufacturing method, a die having at least one groove in an inner circumferential surface of a through-hole is turned and pressed into an original pipe under pressure to perform contraction, and a boss having at least one flat portion in an outer circumferential surface is turned and pressed into the original pipe under pressure to perform the expansion. COPYRIGHT: (C)2006,JPO&NCIPI
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