Researchers throughout the world extensively adopting recycling techniques in order to manage polymer waste. But hitherto, less work has been performed on fabrication of fused filaments based on secondary (2°) recycled acrylonitrile butadiene styrene (ABS) polymer reinforced with industrial waste of Fe powder. In present study, efforts have been made on development of composite filaments for fused deposition modelling (FDM) technique of additive manufacturing by controlling different parameters like speed, temperature and load of twin-screw extruder using recycled ABS reinforced with Fe powder. Total nine composite filaments were prepared by taking 90% ABS and 10% Fe powder by weight. The maximum peak strength (32.82 MPa) of ABS + Fe based composite filament was observed at 15 kg (load), 225 °C (extrusion temperature) and 70 rpm (speed) whereas the maximum %BE (7.13%) was obtained at parametric settings of 10 kg, 245 °C and 70 rpm respectively. The observed mechanical and thermal properties of the composite filaments were analysed through porosity analysis, scanning electron microscopy characterization and differential scanning calorimeter.