Tolerance analysis methods for the application of ISO AND ASME GD&T to mechanical component: 2D and 3D case studies

This study examines the application of two- and three-dimensional tolerance analysis methods in accordance with ISO 2768:2017 and ASME Y14.5-2018 standards to assess dimensional and geometric compliance in mechanical component assemblies. By analyzing a series of case studies—including a simple shaft-hole coupling and a complex pulley assembly—the study compares deterministic and statistical methods, such as Worst-Case Scenario (WCS) and Root Sum Square (RSS), to explore their effectiveness in real-world design. The analysis demonstrates how 3D tolerance methods can capture complex geometrical interactions and cumulative deviations more accurately than traditional 2D approaches, particularly for assemblies with intricate mating features or spatial dependencies. Key differences between ISO and ASME standards, such as the implications of the envelope principle (ASME Rule #1) and the independence principle in ISO, are highlighted to help practitioners choose the appropriate standard for specific applications.