To provide a metal tube formed by providing a sure and stable spiral pattern shape on a metal tube with thin wall thickness by spinning and roughing the outer peripheral surface thereof, and to provide a manufacturing method thereof.
The metal tube has a hollow-core tube body made of metal and has uniform wall thickness of 20 to 50 μm. The metal tube is obtained by spinning while being pressed by a top disposed on the outer periphery thereof. By the spinning, rugged parts are formed on the outer peripheral face and inner peripheral face of the metal tube at a substantially fixed interval. Later, the outer peripheral face of the metal tube is roughened by the spinning by using another top 5a having a tip end angle sharper than that of the top .
Sadao Enjoji
Machida Mitsunobu