In the process of machining 3D surfaces, the cutting tool (tool) often is an end-ball tool, so the position of the contact point (cutting point) between the edge of the cutting tool and machined surface is always altered resulting in the change of the surface finish. With the machining process performed on a CNC machine with more controlled axes, the wide diversity machining methods will be applied. The problem related to difficult-to-reach cutting positions with thin walls could be controlled. Simultaneously, it is possible to create multiple tool approaches to optimize the machining process and heat dissipation in the machining area. In this paper, the variation in surface roughness and microstructure of the machining surface is studied by changing of contact point of end-ball tool (applying different tilt angles for the tool axis). The experimental cutting process was carried out with C45 steel on a four-axis turn-mill machine (EmcoTurn E65), and the CNC machining program was created on NX Cam software.