Abrasive flow finishing (AFF) is one of the advanced finishing processes used mainly for finishing of complex surface features. Nano finishing of aluminium alloys are difficult using conventional finishing processes because of its soft nature. So, in the current work, aluminium alloys are finished using AFF process. Since the finishing is carriedout using polymer rheological abrasive medium (medium), the finishing forces on aluminium alloy workpieces are too low compared to conventional finishing processes. Thus, this process generates nano surface roughness on aluminium alloy. By using the theoretical model, change in surface roughness (ΔRa) with respect to various AFF input parameters is studied. A new simulation model is proposed in current paper to predict the finishing forces and ΔRa during AFF process. Modeling of finishing forces generated during the AFF process is carriedout using Ansys Polyflow. These forces are used as input in the simulation model to predict ΔRa. Medium rheology decides the magnitude of the generated finishing forces in AFF process. Therefore, to predict the forces accurately, rheological properties of the medium are measured experimentally and used as input during modeling. Further, to make the simulation more realistic, abrasive particle bluntness with respect to extrusion pressure and number of strokes is considered. Because of considering these realistic conditions simulation and experimental results are in good agreement compared to theoretical results.