| 摘要 |
PROBLEM TO BE SOLVED: To obtain a spiral pipe excellent in fusion strength over the whole thereof. SOLUTION: A strip plate-shaped profile 10 for a spiral pipe is constituted so that the adjacent side surfaces 12 thereof are opposed to each other to be fused when the profile is wound spirally. The side surfaces 12 to be fused are respectively inclined with respect to the diameter direction of the spiral pipe, that is, inclined with respect to the pressure direction in the fusion.
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