| 摘要 |
PROBLEM TO BE SOLVED: To easily form an outer circumferential projecting portion of a tube without requiring any special tool. SOLUTION: In forming a projecting portion on an outer circumference of a metallic tube 10, a metallic ring 12 having a layer 14 formed of the powder for thermit reaction on an inner circumference is externally fitted to the tube 10, and the ring 12 is welded to the outer circumference of the tube 10 by the thermit reaction. Alternatively, the reactive agent in which the powder for thermit reaction is diffused in the volatile solvent is applied to an outer surface of the tube, the volatile solvent in this reactive solvent is evaporated, and the metallic ring is externally fitted to the applied portion, and the ring is welded to the outer circumference by the thermit reaction. |
