<p>Hot-spots are classified into two types: Type “a”, which refers to weld toes located on the plate surface, and Type “b”, which refers to weld toes located at the plate edge. In this study, fatigue test data on joint details in which Type “b” cracks occur were collected from 25 published papers, comprising a total of 264 data points across several different joint details. Finite element analysis was performed to compute hot-spot stress, with variations in element type and element size near the reference points used for hot-spot stress calculation. When the data were organized according to the nominal stress range, significant scatter was observed in the S–N diagram due to variations in fatigue strength among different joint details. In contrast, when analyzed based on the 4–8–12 mm method, as recommended in the IIW Designer’s Guide, the scatter was significantly reduced. Taking into account data scatter, the lower limit, which is defined as the mean minus two standard deviations, was 95.4 N/mm². These findings indicate that fatigue test results for in-plane gusset welded joints, as well as other joint details, can collectively be assessed using the fatigue design curve of FAT90. Additionally, it was confirmed that variations in element size within the range of 1 mm to 4 mm near the reference points, as well as changes in element type, had negligible effects on the hot-spot stress assessment.</p>