The white ceramic to zirconia based [Al2O3 and ZrO2 ] and of titanium carbide [Al2O3 + TiC ] cutting tools as well as theceramic mixed are widely coveted for the machining operations of relatively hard materials, used within hard cuttingconditions. In this paper, are exposed the results of an experimental study relative for the machining of the steel after annealing42CrMo4 with having a Brinell hardness HB 174, machined by two tools separately, white ceramic to zirconia based [Al2O3 andZrO2 ] and the ceramic mixed [CC650]. The testing series is devoted to the roughness main criteria of the cutting conditionsinfluence of the machined surfaces [Ra, Rz and Rt]. To do this we have made plain factorial trials and based on multi factorial themethod of experimental design, the variable parameters: cutting speed, feed per revolution and the cutting depth. The results, towhich we arrived, show that the white ceramic is comparable to that of rectified surfaces after the machining operation classic.The results comparison show that the machined steel by mixed ceramic give a very good surface states with high cutting speeds[180 ; 250 m/min ] in relation to others cutting tools. The mathematical models expressing the relation between the studiedparameters and the parameters used while the experiments have made the comparison object [Gilbert type, Taylor generalizedmodel] as well as a comparison of theoretical and practical results has been made to the nuance CC650.