... carbon,alloy or stainless steel 3)high quality assurance Product inner gearCertificateISO9001 :2000MaterialCarbon,alloy or stainless steel as you requestTechnicsFree ... , such as forging shaft, forging rings, forging flange, gear shaft, gear rings, cast forgings, etc., especially there are special requirements ... quality assurance system will conduct throughout the entire production. inner gear