| 摘要 |
PROBLEM TO BE SOLVED: To provide a coupling part integrated type inner-outer surface smooth tube excellent in manufacturing work efficiency as compared with that when a synthetic resin strip body is spirally wound and provided integrally with the coupling part without preparing a separate and exclusive coupling. SOLUTION: On a main body 4 with a smooth inner surface and crest parts 2 and trough parts 3 alternately or spirally formed on an outer peripheral surface, the outside of a synthetic resin tube 1 provided integrally with a coupling part 5 of a larger diameter than those of the crest parts 2 is covered with a synthetic resin covering part 7 extruded in a tube shape.
|
