Abrasive flap disc, flap disc, flap wheel, grinding disc,with fiberglass and fiber ABS as backing,suitable for flat welds,angle. Abrasive flap disc, flap disc, flap wheel, grinding disc,1. ... with fiberglass and fiber ABS as backing,suitable for flat welds,angle.2. Constant grinding throughout flap ... (rpm)15,00013,00011,50010,000Grit40 to 320 flap disc