An object needs to undergo both grinding and polishing before and after the plating process. This is to ensure dimensional control as well as the smoothness of the object.
One might be curious to know the difference between grinding and polishing. Grinding involves the usage of different types of grinding stones for different base materials. This is process is able to achieve a surface roughness value of Ra 16 and below. Polishing or buffering on the hand uses buffering wheels which produce a shine on surfaces and the process is able to achieve a surface roughness value of Ra 32. However, there is minimal dimensional control in the case of polishing / buffing.
