nylon abrasive brush 1.Filament:Dupont TYNEX A silicon carbide 2 ... .grit load 30% 4 grit mesh:steel wire,36#--500# Abrasive Brush are used in marble, granite, limestone slate, sandstone, ... for first step.Steel,Steel+36#,36# remove loose material on the surface as well as shaped stone surface.46 ... coarse grinding120# ,180# ,240# rough polishing320 #,500# fine polishing abrasive nylon brush,polishing brush