Abstract: 316L austenitic stainless steel shaft head of stabilizing roll in a hot galvanizing line fractured during working. The fracture cause was analyzed by methods such as chemical composition analysis, hardness and tensile property testing, and metallographic inspection. The results show that a large number of long-strip sulphur inclusions existed in the structure of the shaft head, leading to inhomogeneity of structure and reduction of the material properties. Meanwhile the circumference surface of the shaft head was pretty rough. Liquid zinc infiltrated inside the substrate through surface defects and corroded the substrate. Finally, the shaft head fractured in brittle mode under external loads.