Machining one of the most common manufacturing processes within the industry but it is also a process with extreme conditions in the vicinity of the cutting insert. Due to diversity of physical phenomena involved machining has proven to be complex and difficult to simulate. The chip formation process is in the vicinity of the cutting insert associated with highly localized severe deformations accompanied by high local temperatures rise. Furthermore, the strain rate can in the primary zone be very high (>50000 s -1), far beyond what can be reached with conventional mechanical material tests. Therefore, the possibility to extrapolate the material model outside the calibration range with respect to strain rate is a wanted feature. It is recognized that the mechanical behavior at high strain rate differs considerably from that observed at low strain rates and that the flow stress increase rapidly with the strain rates above ∼1000 s -1. The predictive abilities outside as well as inside the calibration range of the empirical Johnson-Cook plasticity model and a dislocation density based model are compared and discussed with reference to AISI 316L stainless steel. The results clearly show the difficulty of obtaining a comprehensive material model that predicts the material behavior across the loading conditions that can occur in machining with good accuracy and that the accuracy of extrapolation is uncertain