nylon abrasive brush 1.Filament:Dupont TYNEX A silicon carbide 2.Nylon 612 3.grit load 30% 4 grit mesh ... :steel wire,36#--500# Abrasive Brush are used ... It adopt TYNEX®A from DuPont U.S.A(Nylon 612 with grit inside),it has the advantage of ... #,80#coarse grinding120# ,180# ,240# rough polishing320 #,500# fine polishing abrasive nylon brush,polishing brush