S-11P Silver Fine #500–600 SUS430 stainless steel Fine finishing, smoothing wood, plastics, aluminium S-411P Silver Rough #120–220 SUS430 stainless steel General shaping, deburring, removing tool marks BS-3P Black Medium #280–400 SUS430 stainless steel with black coating General-purpose sanding with longer-lasting black finish BS-350P Black Extra Rough #30–40 SUS430 stainless steel with black coating Rapid stock removal, heavy shaping, removing large burrs