metal-cutting operations involve the separation of small segments or chips from the workpiece to achieve the required shape and size of manufactured parts. Chip formation involves three basic requirements: (1) there must be a cutting tool that is harder and more wear-resistant than the workpiece material; (2) there must be interference between the tool and the workpiece as designated by the feed and depth of cut, and (3) there must be a relative motion or cutting velocity between the tool and the workpiece with sufficient force to overcome the resistance of the workpiece material. As long as these conditions exist, the portion of the material being machined that interferes with free passage of the tool will be displaced to create a chip.