Emery Corundum grains F40 are a coarse, natural or fused abrasive powder with a FEPA standard grit size of roughly 400–450 micrometers, prized for high hardness (8–9 Mohs) Origin: Turkey  Type: Abrasive, Abrasives  Packing: 50 Kg & 1000 Kg Big Bags Sectors: Metal, Glass, Ceramic Industries. See Our Abrasive Minerals List