When a workpiece to be cut has not enough ductility to produce flow type chips, cracks are generated on the chip surface periodically and the section of the chip becomes just like the teeth of a saw. As compared with the regular flow type chip, the saw-toothed chip is remarkably thin and long, and requires less force to be produced. In this paper, it is studied that under what conditions and how this type of chip is produced. Due to the embrittlement by the plastic flow in the sub-surface layer made by the preceding cut, the saw-toothed chip is frequently produced in the cutting of ductile metals such as copper, aluminum, α-brass, austenitic stainless steel, etc. The heat treatment of workpiece and the Rebinder effect of liquid also increase the brittleness. The ultimate shear strain of the work material is shown to determine the cutting ratio and cutting force.