Under the framework of EUROfusion, we performed comprehensive mechanical and microstructure characterization of ten Eurofer97 steel variants with varying compositions and heat treatment conditions. We characterized the pre-irradiation fracture toughness of the materials along with their Vickers hardness, tensile properties, and microstructure. Compared with standard Eurofer97, the ten variants didn’t show a comprehensive improvement of mechanical properties. In addition, the composition and microstructures in some variants are adverse to fracture toughness, such as low C contents, coarse grain sizes, partially tempered martensite, lack of precipitates, and non-uniform distributions of coarse precipitates. Further studies will be performed on the same materials after neutron irradiation.