A method for shaping a conical metal tube using a tool that has sealing pistons and a die cavity with a complex contour is described. The die cavity has two ends with a cylindrical portion of the die cavity located at each end. The method includes inserting the conical tube into the die cavity such that the ends of the conical tube protrude into the cylindrical sections of the die cavity. Sealing pistons engage the tube ends and press each tube end against a cylindrical portion of the die cavity to seal an interior space of the conical tube. The tube is shaped by applying pressure to the sealed interior of the tube to force the tube against the complex contour of the die cavity while simultaneously axially compressed the tube by exerting axial forces on the tube ends with the sealing pistons.