Finishing surface has an enormous influence on many important physical phenomena such as contact mechanics, sealing, adhesion and friction. In this paper we will present a brief review of contact mechanics and the influence of different process in the finishing surface as the roundness and roughness. For each process step for ball bearing will be explain and different surface parameter will be measure, also the results will be analyze the influence of the process in the finishing surface. A DOE experimental methodology will be use to reach more accurate results with fewer trails and faster response. Also will present new results and a few comments related to a fabrication process.