Exothermic riser (feeder) sleeves are used to retain the heat in risers and to increase solidification duration. A riser should be enough hot to become the last solidified part in a mould cavity. Thus, risers can feed the other parts to result in sound casting products without cavity like defects. They are particularly preferred for steel and ductile iron casting operations which have high pouring temperatures. Exothermic riser sleeves are a mixture of metallothermic-based exothermic and insulating materials (Al, Fe2O3 and SiO2 etc.) that are manufactured in different sizes and shapes. In the present study, performances of some selected commercial sleeves were evaluated in terms of reaction duration, flammability and temperature change etc. Some thermochemical modelling studies were performed to understand the effect of reactant composition on sleeve performance prior to the performance tests.