Mechanisms of chip formation
Machinability of difficult materials - Application to hardened steels

The cutting mechanisms of hard steels lead to the formation of jagged chips known as "sawtooth" chips, as shown in figure 12.

This type of chip has already been observed at low cutting speeds when machining titanium or nickel-based superalloys with poor thermal properties. Shaw attributes the formation of these localized bands in these alloys to a concentration of thermal energy in them due to their poor thermal properties. In this case, the concentration of thermal energy in very narrow bands could be due to too short a heat dissipation time....