Model for cutting forces in hard turning of bores

For the planning of finishing cutting processes it is also important to know the cutting forces. The magnitude and direction of the cutting forces and their ratio compared to each other have an effect on the machining accuracy. Differently from cutting performed with traditional tools the passive force (F-p) is higher in hard turning and as value in internal turning besides the same technological data - is higher than in machining of external surfaces. In this paper we present the change of forces arising in cutting of hardened bores as a function of the technological data.