Starting from a Hamiltonian based on the random magnetic anisotropy model to describe the magnetic characteristics of amorphous materials such as TbFe2, we determine the low‐temperature dependence of the coercivity as well as the magnetization dynamics of these materials. The results are seen to compare well to experiments whenever data are available. Our model features clusters, each characterized by its anisotropy direction. The exchange‐energy term entering the Hamiltonian is represented by an effective exchange interaction acting in the intercluster regions.