| 摘要 |
PROBLEM TO BE SOLVED: To provide extruded tubes for a heat exchanger, in which even when tube ends are tapered by swaging, all of minute holes are made open in at most 1 mm opening-width, in an arrangement of many rows in the transverse direction of the cross section, and further provide a heat exchanger in which the tubes are used. SOLUTION: Minute holes 2 of at most 1 mm opening-width are arranged axially in the intermediate part of the cross section of the tube in many rows. A pair of end minute holes 4 are formed integrally beforehand longitudinally in a width greater than the holes 2 on both ends of the section. In the sectional ends intersecting with the extrusion direction, parts 5 of an adequately smaller width than the holes 4 are formed by plastically deformed by swaging.
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