The analysis of SCE (specific cutting energy) is vital for determining the machining efficiency. Conventionally, the machining forces are used to determine SCE, which is quantified as the energy that is consumed to remove unit volume of material. To correlate the micro-mechanics of material deformation and small-scale material removal in machining, in this research paper, the SCE has been modelled with consideration of shearing mechanism. While developing the model, small scale material indentation and deformation phenomena have been correlated with complex tool-work interaction behaviour in micro machining. The experiment was conducted for validation of the model for different light-weight materials i.e. Al alloy and Cu alloy. The investigation was done through the analysis of cutting forces and the visual examination of microchip morphology. It was found that the nonlinear increase and sharp fall of specific shearing energy (UShe) occur owing to the variations of the material removal mechanism. This is especially valid for lower values of UCT (undeformed chip thickness). © 2020 Elsevier B.V.