Turn-milling is a new process that uses, turning and milling operations together, so that the tool and the work piece rotate simultaneously, for this reason, it has a wide ability in machining curved and complex surfaces. The main subject of the present study is the experimental and numerical investigation of the effect of changes in independent machining parameters, including work piece rotational speed, tool rotational speed, and tool feed rate, on dependent cutting parameters such as cutting force and specific energy. The result is that, according to experimental tests as well as numerical studies, increasing the tool feed rate increases the cutting force components and reduces the specific cutting energy. According to experimental tests, a threefold increase in the tool feed rate increases the resulting machining force by about 2.3 times and reduces the specific cutting energy by about 27%. A numerical study in the ABAQUS shows a 2.7-fold increase in the resulting machining force and a 4% reduction in the specific cutting energy following an approximately three-fold increase in the tool feed rate.