In electro-discharge machining with mixed powder, the assessment of electrode wear rate (EWR) plays an important role in the field of machining science. Moreover, the fact that two different types of electrode materials were considered under the same technological conditions is an urgent issue. Therefore, in this study, the EDM process with tungsten alloy powder suspended in oil solvent was explored in two types of electrode materials, like graphite and copper to process X40CrMoV51 steel alloy. The results showed that the EWR of each type of electrode is different since their thermal conductivity properties are dissimilar.