The physics of formation of a saw-toothed (or segmented) Ti6Al4V chip in machining is still an ongoing issue in the literature as well as its modelling and numerical simulation. After a review of the theories explaining the formation of such a chip, three finite element models are presented with a desire to take into account the physical phenomena. The results of the simulations are compared with the different theories reported in the literature. This confrontation allows us to keep the most relevant model which contributes to the understanding of the phenomena. It shows that combining the adiabatic shear band and the crack propagation leads to a chip morphology and formation mechanism close to the experimental one. The study also allows to estimate the teeth formation frequency of the numerical chip.