Cambolt that has two slot shape in thread, have been widely used to adjust wheel alignment in Hyundai and Kia motors. These slots in thread make stress more concentrated, and lead to yield more easily. This paper describes the optimizing process of the Cambolt figure, to maximize the yield load. Contribution of the Cambolt design factors to yield load was verified, through actual test and finite element analysis. Using the DFSS (Design for Six Sigma) method, we optimized the design factors of Cambolt, and confirmed the yield load was enhanced. This new Cambolt can provide more stable wheel alignment joints, by using a higher range of preload.