Using a novel ball mill with controlled ball movement we have produced for the first time amorphous Fe50B50and Fe40B60alloys and nanocrystalline Fe80B20and Fe66B34alloys by mechanical alloying. The structural evolution of elemental powder mixtures is studied following milling and subsequent thermal treatment. Upon heating both amorphous and nanostructural mechanically alloyed Fe‐B alloys transform into a mixture of equilibrium phases.