What is orthogonal cutting?

The tool cutting edge is set at 90' to the direction of movement. The effectiveness of the tool depends greatly upon the slope of the active surface of the tool. The tool would tend to curl the chip in the form of a clock spring or a flat spiral. This is not the best form of chip for efficient metal removal. The disposal of such chips present difficulties, particularly in turning as the chip will stay on top of the tool holder and may damage the workpiece's surface.