Abstract: A tool for isothermal forging is disclosed. The tool consists of two die halves, at least one of which consists of an assembly of individual components whose side facing the workpiece is provided with a thin electrically insulating layer. The assembly of the die half from individual components occurs following forming of the components by casting and/or forging, and machining of the formed components. The forming of the die halves from separate components makes it possible to adapt the components of the die half to the particular working conditions in an optimum manner. The provision of an insulating layer on the individual components reduces the risk of local welding and nonuniform temperature distribution during inductive heating.