This analytical and experimental research deals with the chip-breaking characteristics during turning operations. To assess the chip-breaking characteristics a new parameter called the chip-breaking index, C B , is developed. This index is defined based on the thickness and length of the broken chip. The shape of broken chip, chip-breaking cycle time and specific cutting energy are appraised to determine the optimum cutting conditions for effective chip-breaking. Properly controlled chips were produced with the C B values under 0.2. When the C B values exceeded 0.2, the chips were found to be over-controlled, regardless of the work materials and types of chip former used.