... Grit G16,size,1.4mm 2.Alloy steel material 3.ISO9001 ,SAE 4.Durability 3000times 5.Hardness,41-63HRC Cast Steel Grit1 ... /G80/G120/ etc2.Diagram 2.5mm/2.0mm/1.7mm/1.4mm/1.2mm/1.0mm/0.7mm/0.4mm/0.3mm/0.2mm3 ... .Made of quality steel shot reach to SAE, ISO9001.4 ... . The production include some chemical C 0.85-1.20%, Mn 0.60-1.20%, Si 0.40-1.20 ...