*2.5. Roughness Measurement*

The final roughness of the samples after machining was measured in a Mitutoyo Surftest SV-2000 equipment (Figure 3). The roughness profile and the average roughness value (*Ra*) were measured along 4 mm in the middle of cutting passes 5, 9, 13, 17, 21, 25, 29 and 33. In Figure 4 the accurate lines where roughness was measured can be seen.

**Figure 3.** Measurement of final roughness in a sample.

**Figure 4.** Roughness measurement lines.
