In context of industrial mass production of automotive components, innovative high performance manufacturing technologies offer maximum efficiency at low unit costs. Regarding for example motor housings for electrical vehicles, aluminum cast alloys are popular materials. Mostly they are primary shaped by die casting in high quantities. In a following stage of production, detachable joints can be made highly efficient by the technology of helical thread forming. By minimizing the tool path, main process time is reduced to 35 % towards conventional tapping. This study analyzes the impact of T6 heat treatment of AlSi10MnMg on the tapping process by mechanical tool loads measured. In order to evaluate the thread quality, surface roughness and thread profile are analyzed between as-cast and T6 condition comparatively. Results of the higher material strength are increased tools loads while thread forming process on the one side and higher surface quality on the other. Finally, the results of this study contribute to specific fitting of machining or head treatment conditions to the desired performance properties.