Correct heat treatment and machining processes are fundamental for the functional behavior and fatigue strength of stress-imposed components. Until now, the only methods in common practical use to evaluate surface areas of parts and components are conventional techniques such as metallurgy, X-ray diffraction, and conventional hardness testing techniques. However, these techniques cannot easily be integrated into production processes, as their testing speed is too slow and as some of these techniques are also destructive. Nevertheless, the results obtained from these techniques can be used for a statistical process control.