CNC fixtures are essential workholding systems that control part position, support weak areas, and resist machining forces. A well-designed fixture improves accuracy, repeatability, operator efficiency, and production stability. From the 3-2-1 locating principle to advanced pneumatic, vacuum, magnetic, and quick-change systems, fixture selection should be based on the part’s geometry, material, tolerances, machining operations, and production requirements. For repeat precision manufacturing, fixture planning is often a key factor in achieving consistent quality and efficient output.