Corrosion is the degradation of metals due to electrochemical reactions with their environment. In mild steel train walls, corrosion accelerates structural damage, necessitating effective surface treatment methods. Sandblasting, a key surface preparation technique, enhances adhesion and corrosion resistance by increasing surface roughness. This study investigates the impact of different abrasive materials silica sand, aluminum oxide, and steel grit on the surface roughness and corrosion rate of SS400 mild steel. Specimens (80 mm × 80 mm × 2 mm) were prepared and treated via sandblasting, followed by surface roughness measurements and electrochemical corrosion testing. Results showed that steel grit produced the highest surface roughness (62.08 µm), while silica sand yielded the lowest corrosion rate (0.0000175 mm/year). Despite its lower roughness, silica sand demonstrated superior corrosion inhibition, suggesting that optimal abrasives for SS400 steel depend on balancing roughness and electrochemical performance. These findings provide critical insights for selecting abrasives in industrial applications, particularly for train wall maintenance.