Method and device for work-hardening a crankshaft

A method for the work hardening of a crankshaft which has connecting-rod bearing journals, main bearing journals and crank webs, wherein the connecting-rod bearing journals and the main bearing journals have oil bores, wherein the oil bore end has a bevel and/or has a transition radius at the transition to a running surface of the respective journal, wherein the transition radius and/or the bevel of at least one oil bore end of one of the oil bores of a respective journal is work-hardened by an impact force being introduced into the oil bore end by an impact head having a shaping portion whose shape is adapted to the transition radius to be hardened and/or to the bevel of the oil bore end, wherein an impact tool comprises the impact head whose shape is adapted to the transition radius to be hardened and/or to the bevel of the oil bore end, wherein, the impact tool comprises at least two impact heads, each impact head of the at least two impact heads having a different diameter for the impact hardening of the oil bore end, and the impact heads of the at least two impact heads of the impact tool penetrate to different depths into the oil bore end during the impact hardening and wherein a changeover device exchanges the impact heads of the at least two impact heads of the impact tool.