Dataset corresponding to the following manuscript:  Slagter, A., Setyadji, J.A., Vogt, E.L. et al. Nanoindentation Hardness and Modulus of Al2O3–SiO2–CaO and MnO–SiO2–FeO Inclusions in Iron. Metall Mater Trans A (2024). https://doi.org/10.1007/s11661-024-07330-x The dataset contains raw nanoindentation data both in .hys (Hysitron software) and .txt format, as well as the files used for post-processing of the data. It also contains thermodynamic simulation files produces with Thermo-Calc software and its correspondig results exported to .txt format