Production method of cold drawn seamless steel tube

First, no mandrel pulling (when drawing only with the drawing tube die do not need mandrel);

Second, the short mandrel pulling system (when pulling the pipe mold and axial fixed length of the short mandrel);

Three, long core rod drawing (drawing when using pull pipe mold and with the steel pipe moved with the length of slightly larger than the length of the pipe long mandrel); Four, the traveling Mandrel pulls the system (pulls when uses pulls out the pipe mold and does not make the axial fixation to be able to maintain stably in the deformation area the short mandrel). In the meantime, the first two are widely used in production; the coreless rod is used to reduce the outer diameter of the steel pipe, and the other three kinds of drawing with mandrel are used to tighten the thickness of the steel pipe, and there is a certain reduction deformation.