Abstract
Shape controlled extrusion apparatus was developed to fabricate an aluminum square pipe with changing it's inner and outer size during extrusion. The inner size of the pipe was changed by shifting a tapered mandrel, and the outer size was also changed by shifting four segment dies It was found that the plasticine square pipes with the extrusion ratio of 2-6 are produced using this apparatus. Finally, extrusion of A1050 aluminum alloy was performed.