In Fig.4, four insert engage into the generation of the surface profile, whereas the profiles of the two insert are missing. In Fig.6, two insert only make the surface profile, since the feedrate is lower than in Fig. 4 . The maximum surface roughness of Fig.4 is about 8 µm, and that of Fig.6 is about 4µm. The same cutting conditions and the same runouts are used in Fig. 4 and 6, except for the feedrate.