Abstract Soft magnetic materials are ubiquitously utilized in various applications such as motors, actuators, sensors, and so forth. The requirements for efficient cores in electric power transmission devices include low core loss and high saturation magnetization. Here we report the magnetic properties of Fe-based soft magnetic alloys with the compositions Fe 67-x Co 20 Ti 7 Zr 6 B x (x = 0, 2, 4, and 6 at.%) produced by melt-spinning. The highest saturation magnetization achieved is 190 emu g −1 (1.79 T) for the Fe 67 Co 20 Ti 7 Zr 6 system. This performance is attributed to the uniform distribution of nanometer-sized α-Fe nanocrystals. In addition, the experimentally measured magnetic properties are reproduced well by micromagnetic simulations.