In this study, best-fit fatigue curves are constructed considering material properties and loading modes. Three common fatigue test methods (rotating bending, axial load-control, and strain-control) are compared, and their scopes of application are clarified. The best-fit fatigue curves, expressed as functions of ultimate tensile strength, have been constructed based on strain-controlled fatigue test data. A comparison of the best-fit fatigue curves with axial load-controlled test data reveals that both deviated from each other for the carbon and low-alloy steels, and austenitic stainless steels. Therefore, the best-fit fatigue curves are reconstructed by integrating data from both rotating bending and axial load-controlled fatigue tests. For the carbon and low-alloy steels, the best-fit fatigue curves are classified according to two types of microstructures, whereas for the austenitic stainless steels, the best-fit fatigue curves are classified according to two types of loading modes. Finally, design factors based on the reliability of the best-fit fatigue curves are explicitly presented.