For extensive applications of bulk metallic glasses as structural materials, Fe-based bulk metallic glasses Fe73.8−xC7.0Si3.5BxP9.6Cr2.1Mo2.0Al2.0 (at.%, x = 3, 5, 7, 9) have been developed using hot metal, commercial grade pure elements, and industrial ferro-alloys. The alloy Fe68.8C7.0Si3.5B5P9.6Cr2.1Mo2.0Al2.0 can be cast into a fully amorphous rod of 5 mm in diameter through a suction casting method. The glass forming ability of the alloys can be successfully assessed by the difference of Gibbs free energy between liquid and solid phases obtained through thermodynamic calculations.