Sandpaper Grit Scales - seabean
ISO/FEPA (P-scale) Finishing Scale Grit Particle Size in Microns Particle Size in Inches 4.5 1842 0.07252 P12 1815 0.07146 P16 1324 0.05213 16 4 1320 0.05197 P20 1000 0.03937 M 20 3.5 905 0.03563 P24 764 0.03008 A 24 3 715 0.02815 30 2.5 638 0.02512 C P30 642 0.02528 36 2 535 0.02106 R P36 538 0.02118 40 1.5 428 0.01685 O P40 425 0.01673 50 1 ...