... American standard series.standard sprocket, idler sprocket, stainless steel sprocket,chain sprockets etcMaterial: C45, A3 steel. other material is also avaible ... customer's requestment.type: 08B, 10B, 12B, 14B......, in single, double, triple row.ANSI, ISOTreatment: forging, hobbing, blackening, quenching. CNC machine processing ...