METHOD FOR STRETCHING METALLIC TUBE

PROBLEM TO BE SOLVED: To draw a thin wall tube without generating breaking of a tube stock and to improve yield by taking the length of a guide member in the vicinity of the inlet side of a working die as specified times of the outside diameter of the tube stock. SOLUTION: By mounting and arranging a cylindrical guide member 50 in a mandrel 3 part in the vicinity of a plug 2 so as to be situated in the vicinity of the inlet side of the working die 4, drawing of the tube stock 1 is executed. The cylindrical guide member 50 whose length L is three or more times as long as the outside diameter D of the tube stock, whose outside diameter is formed slightly smaller than the inside diameter of the tube stock 1 and radius of curvature chamfering is applied to both ends. In this way, even when thin wall products which have the ratio t/D of thickness (t) to the outside diameter D of