Machining of heat resistant aerospace materials such as Inconel 625 or Inconel 718 is characterized by low cutting speeds, high tool wear rate, and high production costs. The machinability of heat resistant super alloys is low due to high hardness and low thermal conductivity of the nickel-based alloys. The paper presents a study on turning of Inconel 625 with ceramic cutting tools with different methods for application of cutting fluid. It is shown that high-pressure cooling gives excellent chip breaking. The tool life of ceramic cutting tools is not improved by increased coolant pressure