A new dynamic cutting force model with nominal chip thickness is presented for predicting the stability of interrupted turning, in where the dynamical cutting force is defined by a function of nominal chip thickness and dynamical chip thickness. The stability lobes of interrupted turning are obtained based on full-discretization method and Floquet theory. Both numerical and experimental tests demonstrate that there is a strong correlation between the nominal chip thickness and the interrupted turning stability, and the proposed model is proved effective for the interrupted turning process.