| 摘要 |
PROBLEM TO BE SOLVED: To provide a metallic tubular body having great durability against deformation both in the axial direction and in the circumferential direction, and to provide a manufacturing method thereof.SOLUTION: The rolling direction of an outlined arrow 2 is allowed to be the circumferential direction of a metallic tubular body 4 so that a metal plate is rounded cylindrically. A butting part 41 of the metallic tubular body 4 is subjected to plasma welding (microplasma welding), thereby to integrate the metallic tubular body 4. Rollers 52, 52 are pressed onto the outer peripheral surface 43 of the metallic tubular body 4, and the rollers 52, 52 are moved in the axial direction of the metallic tubular body 4, thereby to perform spinning. The metallic tubular body 4 is narrowed by being plastically deformed in the axial direction of the metallic tubular body 4, and lengthened in the axial direction. |
