Experimental data show that the magnetic permeability/temperature curves of the alloys investigated have distinct maxima which were shifted from 0 to 120 degree C with increasing nickel content and increased in magnitude by molybdenum addition. The permeability of an Fe-34. 5Ni-2Mo alloy was 55,000 at 25 degree C and 4 ma/cm. The permeability and saturation induction of this alloy are comparable to those of Fe-Ni alloys of higher nickel content. Specific resistance was considerably higher at 0. 9 OMEGA mm**2/m. The Curie temperature of 160 degree C is comparable to that of highly permeable ferrites. Explanations of the findings are suggested.