Mold for partially shortening circumference of tube billet and using method of mold

Abstract

Disclosed is a mold for partially shortening the circumference of a tube billet and a using method of the mold. The mold comprises an upper mold, a lower mold and a mold core used for being inserted into a tube cavity of the tube billet, wherein the upper mold is provided with an upper mold cavity, the lower mold is provided with a lower mold cavity, and the upper mold cavity and the lower mold cavity are matched to form a mold cavity. After the mold core is placed in the mold cavity, a tube billet deformation cavity is formed in the mold cavity; and the upper mold cavity and/or the lower mold cavity are/is in the shape of a flaring, the two sides of the flaring are arc-shaped, and included angles are formed between the two sides of the flaring and the moving direction of a movable mold.

Dependencies are inferred from the claim text.