A versatile vibrating‐sample magnetometer has been developed which measures the magnetization of metal hydrides as a function of magnetic field, hydrogen pressure (up to 6 MPa), and composition, temperature, and time. For the ferromagnetic NdCo5Hxsystem, magnetic properties of well‐defined hydrides and hydride‐phase transformations are studied by this method. The existence of a hydrogen‐rich phase in the NdCo5Hxsystem, the &ggr; phase, is indicated by the temperature dependence of magnetization under the influence of high pressure hydrogen.