The magnetic properties of spheroidal and flake graphite cast irons of similar composition cast into sand moulds of various diameters were measured, and the results obtained were as follows : Under the same degree of graphitization, the maximum induction, the coercive force and the hysteresis loss of spheroidal graphite cast iron were lower than those of flake graphite cast iron, and so the maximum permeability and the residual induction were higher. With increasing degree of graphitization, the maximum permeability increased, whereas the other four quantities decreased
