New technological process consisting of hard turning followed by belt finishing, in place of the widely used method in industry, e.g., grinding, has lately been launched in the automotive industry. This is because, many transmissions parts, such as synchronizing gears, crankshafts and camshafts require superior surface integrity along with appropriate fatigue performance. This paper provides a modelling of part residual stresses produced after belt finishing in order to provide some explanations about the experimental results previously obtained. Indeed, it has been shown that the belt finishing process improves very significantly the surface integrity by the induction of strong compressive residual stresses in the external layer. The model has confirmed this trend. It has also revealed that, among the process parameters of the belt finishing technique, the lubrication appears as a key parameter to get compressive stresses, whereas the elementary force on each abrasive grains influence the depth of the affected layer.