... we pursuit 2)Material:carbon,alloy or stainless steel 3)high quality assurance ProductHelical gearCertificateISO9001 :2000MaterialCarbon,alloy or stainless steel ... requirements, 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. Helical gear