Magnetic properties, electrical resistivity, Vickers hardness, and thermal expansion were measured for Fe–Ta alloys containing less than 7.0%Ta, Fe–Mo alloys containing less than 14.1%Mo, and Fe–W alloys containing less than 13.8%W. Specimens investigated in this study were prepared from fine wires 0.5 mm in diameter by cold-drawing to more than 50% reduction in area after melting in vacuum and subsequent water-quenching from temperatures below 1473 K. Next, all the fine specimens were reheated at 673–1273 K for periods less than 18 ks.The results indicated that the magnetic properties of those alloys depend largely on Ta, Mo and W contents, water-quenching temperature after solution treating, reduction in area by cold-drawing, and reheating treatment. The Fe-2.9%Ta alloy reheated at 973 K for 1.8 ks after water-quenching from 1323 K and subsequent cold-drawing to 97.2% reduction exhibited the magnetic induction B8=1.78 T at 8 kA·m−1, the residual induction Br=1.59 T, the squareness ratio Br⁄B8=0.89, the coercive force Hc=0.95 kA·m−1, the squareness factor \sqrt(BH)max⁄BrHc=0.92, the electrical resistivity ρ=0.127 μΩ·m, Vickers hardness Hv=209, and the mean thermal expansion coefficient αT=13.0×10−6 K−1 at 273–313 K. The Fe-10.2%Mo and Fe-10.2%W alloys reheated at 1073 K for 1.8 ks after water-quenching from 1273 K and subsequent cold-drawing of 97.2% reduction exhibited the following values. In the case of the former alloy, B8=1.62 T, Br=1.49 T, Br⁄B8=0.92, Hc=1.91 kA·m−1, \sqrt(BH)max⁄BrHc=0.83, ρ=0.251 μΩ·m, Hv=290 and αT=11.4×10−6 K−1; in the case of the latter alloy, B8=1.79 T, Br=1.71 T, Br⁄B8=0.95, Hc=1.75 kA·m−1, \sqrt(BH)max⁄BrHc=0.86, ρ=0.215 μΩ·m, Hv=275 and αT=12.0×10−6 K−1.