A method of forming an impeller for a torque converter is provided. The method includes providing an impeller shell including a back axial surface for facing away from an interior of the torque converter, providing an impeller hub including an outer circumferential surface and forming a weld joining the impeller shell and the impeller hub. The weld is contiguous with the back axial surface of the impeller shell. The weld is also contiguous with the outer circumferential surface of the impeller hub. The weld includes a root where the impeller shell and the impeller hub meet the weld. The method also includes machining the root. An impeller for a torque converter is also provided.