The estimation of low-cycle fatigue life for the notched components is one of the most important technologies for the structural metals. In this study, the low-cycle fatigue tests were carried out using the smooth round bar specimens and the notched plate specimens with several stress concentration factors. The materials used are the hot-rolled low-carbon steel sheets, SM400A, SM400B and SM490A. After analyzing the experimental data, the effect of material strength on low-cycle fatigue strength and the estimating method of low-cycle fatigue strength of notched components have been clarified.
