This paper uses multiple fatigue crack growth models to investigate the cyclic growth of fatigue cracks in a shaft. Crack growth is predicted using three fatigue crack growth models: Paris Law and Walker using experimental results to support these predictions. Accurately predicting the growth of cracks in shafts under cyclic loading is the primary challenge because currently used models frequently show variations in practical applications, which may result in failures. By comparing model predictions with experimental data, this study evaluates the accuracy of various models and advances our knowledge of fatigue crack behaviour in real-world situations. As a conclusion, no single model is generally ideal; the choice depends on the specific conditions and material properties. Through the improvement of predictive tools for maintaining mechanical components and boosting safety and performance in engineering applications, this study aims to assist engineers in choosing the most suitable model.