Systems and methods for management of material stresses present at transitions between facets of an anvil and the anvil shaft are described. In one aspect, an apparatus includes an impact tool anvil extending along an axis of extension and having a faceted drive end and a shaft body which is connected to the faceted drive end through a transition region that couples respective faces of the faceted drive end to the shaft body, the transition region including a sweeping radius surface having a first axial end and a second axial end, the first axial end connected to a respective face of the faceted drive end, the first axial end having a tangency with the respective face of the faceted drive end; and an angular transition having a slope that radially rises from the second axial end of the sweeping radius surface to the shaft body.