GB/T 4337-2025 is a special project standard for fatigue test of metal materials, specifying swirl/spin bending method Test method. The standard specifies the test principle (applying swirl/spin bending load to the sample to fatigue failure), instrument requirements, operation steps and result calculation and representation. It is suitable for fatigue performance detection of various metal materials. It can unify the detection method and ensure the accuracy of the data. It provides a reliable technical basis for material selection, product fatigue life assessment and structural safety design.