Tool forces and surface finish are often used as measures to evaluate the performance of a machining process. Cutting parameters have their own influence on the forces and surface finish. In this study, the forces and surface finish produced during turning of hardened EN31 steel (equivalent to AISI 52100 grade) have been analyzed. Uncoated cubic boron nitride insert was used as a tool. Regression analysis was made to establish the dependency of force and surface roughness on cutting parameters. The predictions from the developed regression equations were compared with the measured forces and roughness data. Analysis of variance was undertaken to measure the goodness of fit of the measured data. The models, developed for prediction of forces and surface roughness, were found significant. The most significant parameter affecting the forces was the depth of cut. Feed was also found to be a significant parameter. In most of the cases, cutting speed had only a marginal influence. The influence of cutting speed, feed and depth of cut on the forces was studied. A favorable range of the cutting parameter values was obtained for energy-efficient machining. It was also established that for the conditions of most efficient cut, the surface finish produced was reasonably acceptable.