Abstract: Segment openings are formed in a metal sheet separated by uncut sections at a first processing station, which define an inner blank portion of the metal flow opening. At a second processing station, the uncut sections and the inner blank portion initially transfer stress around the segment openings and across the interior flow opening during a forming operation. During the forming operation, a protrusion of one mold member contacts a first side of the inner blank portion of the interior flow opening. In addition, another mold member is contact the opposite side of the metal sheet so that the mold members cooperate to separate all but one of the uncut sections by which the inner blank portion remains attached to the metal sheet. In this way, the interior metal flow opening is completed without piercing the metal sheet at the second processing station during the forming operation.