This study allows to analyze the influence of the teeth number of the milling cutter during end milling machining on the surface quality, mechanical characteristics, cutting forces, are valuable in terms of providing high precision and efficient machining in order to give a new approach to improve the surface quality of a mechanical part, reducing residual stresses, cutting forces by the material removal process. The Surface roughness is particularly sensitive to the runout errors of the insert, number of cutter teeth and the nose radius during this type of machining. This paper is a comparative study of the surface finish, stresses, and cutting forces when machining with a 2, 6 and 8 tooth cutter under the same cutting conditions. In addition to the investigations on the surface integrity and the comparative geometrical study, we have provided a calculation tool to simulate the influence of the residual stresses and the loads applied on the mechanical part. This approach examines the characteristics of the surface topography of aluminum parts, a stainless steel tool and the material strength of this part in general. The investigation is carried out by several simulated and realizable tests and performed on the HPC unit and the machine tool by exploiting the finite element method in the case of stable machining. The exploitation of the finite element method has led to promising results in terms of propagation of the machined surface state, residual stresses and cutting forces which have a considerable effect on the wear on the main edge of the cutter. The simulation shows that the roughness of the surface condition is inversely influenced by the teeth number of the end mill, the cutting forces as well as the residual stresses.