For the G65 test, selective removal of the matrix contributes to an increased roughness compared to the smooth surface of the PM steel on Fig. 8b. For the CT test, deeper grooves are observed on Fig. 9d, indicating that the tool steel also wear by a microcutting mechanism. It is here worth noting that the observed groove is larger than the small secondary carbides. Hence, it is likely that under these conditions the abrasive particles are able to remove these secondary carbides. Several scratches and small grooves are observed below the surface in Fig. 9d. These defects are considered to be due to the sample preparation process and are not related to the wear process.