The plate for the multi-stage reducer is a component of a traveling motor and is required for high wear resistance and maintaining precision. The plates that are mainly manufactured by the press process have burrs on the edges of the material after the general press shear process. Since burrs have a great influence on assembly and shape precision according to product characteristics, a post-treatment process for removing burrs is mandatory, and several studies have been conducted on this topic. In this study, a flattening process was developed to remove the burrs. First, the piercing and blanking process forming analysis was performed to find the process conditions for burr removal. Subsequently, the flattening process forming analysis was performed, and the reliability of the analysis was verified through an experiment using the derived process conditions.