Effective workholding in CNC machining requires sufficient force to prevent movement while avoiding distortion from excessive pressure. This article reviews distortion mechanisms, traditional vises and chucks, and advanced vacuum, magnetic, and adaptive solutions. Shop examples and journal studies demonstrate practical methods to distribute clamp loads evenly, monitor forces in real time, and integrate fixturing with toolpath strategies. Implementation of these techniques routinely achieves flatness and roundness tolerances below 0.002 inches across aluminum, steel, and titanium components.