In the transitional cutting process such as milling or grinding, there exist transient regions (elastic deformation region and plastic deformation region) in the initial part of contact between tool and workpiece. These regions are left in the finished surface and affect the surface generation mechanism. From the above point of view, a model experiment is conducted to account for the mutual interference state between tool and workpiece. Variations of cutting forces and various residual stocks in the elastic, plastic and cutting region in the initial part of contact are analyzed experimentally. Furthermore, the effects of different machining conditions on the sliding phenomenon of a cutting edge are investigated. The results show that the sliding length decreases with an increase of the interference angle, and that plastic deformation and cutting begin at respective constant depth. It is also found that the sliding length increases with an increase of the width of cut and the nose radius of a cutting edge, while the sliding length decreases with an increase of the system stiffness.