摘要 |
<p>An aspect of the present invention provides a method for producing an ultra thin wall metallic tube by a cold rolling method with significant wall thickness reduction. In a method for producing the metallic tube with a cold pilger mill, a wall thickness is reduced to perform elongation while a wall thickness center diameter is expanded using a pair of rolls, which has a tapered groove die whose diameter is gradually expanded or reduced from an engaging inlet side of the roll toward a finishing outlet side thereof, and a tapered mandrel bar, whose diameter is gradually expanded from an engaging inlet side of the tapered mandrel bar toward a finishing outlet side thereof.</p> |