CAM systems are effective SW tools for creation of toolpaths for milling of complex shape parts. Nowadays, many parts are made of difficult to cut materials. Machining of these materials needs to maintain the required cutting conditions. However common CAM systems are currently lacking the control of the real cutting conditions at the contact point between the tool and workpiece. Therefore the project intends to achieve the new module (CAM4speed module) of CAM to optimize the spindle speed and feed-rate to maintain the constant cutting speed and constant feed per tooth at the contact point. Significant machining time savings, improvement of machined surface roughness and significant increase of the tool life were achieved when using of the very first version of this optimization in the form implemented to postprocessor. The main outcome is the new CAM4speed module (in the form of the general library that can be implemented into any CAM system) including the optimization function. The second outcome is the plugin of this CAM4speed module for Siemens NX CAM. The third outcome is the verified technology of spindle speed and feed rate control to achieve constant cutting speed and feed per tooth applied during machining of specific part.