Out-of-roundness is crucial for the proper functioning of individual products or parts in a machine. Mechanical components often consist of circular elements that require precise alignment. These circular parts are used in critical areas of the machine, and the shape characteristics of each component can significantly impact overall performance. In this study, we focus on a specific specimen and use three different methods - the Diameter method, Radius method, and Three-point method - to measure its out-of-roundness. The collected data is then analyzed using one-way ANOVA to propose an effective out-of-roundness measurement technique suitable for industrial settings.

Due to industrial development, the importance of GD&T tolerance is growing day by day. Roundness measurement means the size deviated from the ideal circle. Roundness evaluation methods include LSCI, MZCI, MCCI, and MICI. In this experiment, measurement deviations according to roundness measurement methods such as radius method, diameter method, and three-point method were studied using the same roundness specimen. The measurement method was measured 20 times each by the measurer, and the average value and dispersion of each data obtained through the experiment were confirmed. Through the experiment, it was confirmed that the diameter method, the three-point method, and the radius method were measured and spread out in the order of magnitude. In addition, the interrelationship according to each measurement method was confirmed using the experimental design method. The test statistic value (P) was greater than 0.05 through hypothesis testing, and the null hypothesis was rejected and the alternative hypothesis was adopted in the experiment.