I'm trying to find the correllation between various fine grit sandpapers (600, 1000, 1200, etc.) and the resultant average surface finish (Ra) created when sanding 6061-T6 aluminum. The goal is to determine if we need to polish or sanding is sufficient to obtain an average 12RMS surface finish for an environmental face seal.

Does anyone have, or know where this information resides?

Thanks

Paul_F