Removing material does not induce stress. The stress exists in the material (assuming the material was not properly stress relieved prior to machining) so the removal of material actually removes stresses which existed before. Material which has been properly stress relieved is inert and the only way machining will induce stress is if the operation is one which deforms the material rather than cutting it. So, a very dull cutter could induce stress as could a swaging operation. GD
