Freeform parting surfaces frequently incorporate all of the above shutoff types in one free-flowing shape. All of the considerations of all the other shutoff types still remain important to maintain tool longevity. Freeform parting however introduces another factor, that of knife edge metal conditions. As the parting surface traverses along the side of a part it can freely transition from one orientation to another. As these transitions occur, it is imperative that the parting surface remain very close to normal to the part face to prevent the occurrence of knife edges.