Although thixoforming of low melting point alloys as aluminum or magnesium is now an industrial reality,thixoforming of high melting point alloys as steel is still at the research level.High working temperature,die wearing and production rate are problems that must be solved and are under investigation.The aim of this work is to evaluate the thermal and mechanical loadings applied to the tools during the steel thixoforging process in order to determine whether classical hot-work tool steel can be an appropriate tool material.This evaluation has been realized thanks to experimental trials and to simulations on the finite elements code Forge2008.The effect of the loadings on the tool’s failure modes are highlighted and compared with the ones observed in classical hot forging.Beyond this,the failure modes of hot-work tool steel,the X38CrMoV5 or H11,were presented. Thixoforming of low melting point alloys as aluminum or magnesium is now an industrial reality, thixoforming of high melting point alloys as steel is still at the research level. High working temperature, die wearing and production rate are problems that must be solved and are under investigation. aim of this work is to evaluate the thermal and mechanical loadings applied to the tools during the steel thixoforging process in order to determine whether classical hot-work tool steel can be an appropriate tool material. This evaluation has been realized thanks to experimental trials and to simulations on the finite elements code Forge 2008 . The effect of the loading of on the tool’s failure modes are highlighted and compared with the ones observed in classical hot forging.Beyond this, the failure modes of hot-work tool steel, the X38CrMoV5 or H11, were presented.