Incremental sheet formingwith activemedium (IFAM) is a flexible manufacturing process that creates concave–convex sheet metal parts in one clamping without needing a counter tool or a die. In the first study of this new process (Ben Khalifa and Thiery in CIRP Ann 68(1):313–316, 2019, [1]), a conventional hemispherical tool has been used in interaction with pressurised air to manufacture concave–convex parts. Since the geometric accuracy was not satisfying, within the present study, a conical tool with a dedicated angle is introduced to IFAM. The idea behind this tool concept is to restrict the inclined part wall to a target angle. At first, results from the numerical investigation show an improvement of the accuracy when a conical tool is used to manufacture a truncated convex pyramid. Subsequently, experiments validate the numerical model and reveal increased process reliability. The experimental investigations of truncated convex cones and concave–convex parts close the paper and underline the feasibility of the tool concept.