High-speed turning of a carbon steel with a rotary cutting tool

The self-driven rotary cutting tool of which bearing was cooled and lubricated by an oil mist with large amount of air was newly developed and applied to the high speed turning (up to 900 m/min) of 0.45% carbon steel. The effect of the coolant supplied to the bearings was evaluated. Cutting force and cutting temperature were also measured. The results indicated that the cooling by large amount of air was useful for reducing the temperature in bearings, which temperature depended on the axial and the radial load of the bearing. The cutting temperature with the self-driven tool was considerably lower than that of the fixed tool, while the cutting forces of these tools were almost the same. The decrease of the temperature was due to the decrease of the sliding speed of the chip on the self-driven tool.