1.The first difference between facing, turning and milling operation is that, in facing and turning, the material block or part to be machined is rotated, while in milling, the tool is rotated.
2.The turning and facing tools are single-point cutters, while the milling tools are usually multi-point cutters.
3. In the turning operation, the tool generally reduces the diameter of the cylindrical workpiece, which can be done by cutting into the part for some depth and move the tool parallel to the axis of the part. While facing operation reduces the length of the piece, the tool is moved perpendicular to the axis of the part. In milling operation, the cutter rotates and removes material by moving along a particular direction and angle of the axis of the workpiece.
4. Facing is not restricted to workpieces with cylindrical profiles. Using a 4-jaw chuck, you can face rectangular or odd-shaped work to form cubes and other non-cylindrical shapes.