METHOD FOR REDUCING DIAMETER OF METALLIC PIPE

摘要

PROBLEM TO BE SOLVED: To expand the working ratio of tube drawing in the case of reducing a diameter and to reduce the number of tube drawings from a base pipe to a product size thereby by arranging a plurality of drawing dies with a certain interval on the die holder of a tube reducing machine and filling gaps on this side of the drawing die of a first stage and before and behind a drawing die with a lubricant. SOLUTION: The drawing die 3-a of the first stage and the drawing die 3-b of the second stage are set in the die holder 1 of the tube reducing machine with a certain interval and lubricating oil 4 as the lubricant is supplied to the part on this side of the drawing die 3-a of the first stage and the gaps between the drawing die 3-a of the first stage and the drawing die 3-b of the second stage. One-pass tube drawing is executed by executing two continuous drawing of the metal pipe 2 with the drawing die 3-a of the first stage and the drawing die 3-b of the second stage while flowing the lubricating oil on both of the dies and pipe.