Having chosen a particle size, another important parameter that must be considered both for the lapping and polishing processes is the MRR, which is related to the rotational speed of the lapping/polishing plate and the load applied on the sample. Fig. 2 shows the MRR and the sample roughness with different pressures applied on the surface. It can be seen that with increased pressure, the MRR clearly increased. Nevertheless, there is not such a correlation between pressure and roughness. At low applied pressures, there is barely any interaction between the sample and the lapping pad, resulting in very low MRR. For applied pressure higher than 27 kPa both roughness and MRR slightly increase which could be due to the high friction shear forces [10] on the sample. As a result, an optimal lapping applied pressure of 27 kPa has been chosen to be used with the optimal abrasive particle of Al2O3 3 µm.