Abstract Iron silicon carbide Fe 0.79 Si 0.09 C 0.12 was prepared by mechanical alloying from elemental powders, with a ball‐to‐powder weight ratio of 20:1. This synthesis was carried out in two stages: in the first stage cementite Fe 3 C was prepared from elemental iron and carbon powders, the mixed powders were milled for 30 hours. In the second stage Fe 0.79 Si 0.09 C 0.12 was prepared from cementite Fe 3 C and Silicon elemental powder as precursors, the samples were milled for 1, 3, 5, 10, 15, 20, 25, 30 and 35 hours. The alloy progress for each milling time was evaluated by X‐ray diffraction (XRD) and 57 Fe Mössbauer spectrometry. Nanocrystalline Fe 3 C powders were obtained from Fe and C, with an average grain size of 15 nm. It was possible to prepare metastable iron silicon carbide such as Fe 0.79 Si 0.09 C 0.12 and Fe 0.81 Si 0.02 C 0.17 and their respective hyperfine parameters are reported. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)