... requirements. The main technical parameters of gearStandard of materials: GB/T3077-1999The grade of materials: 45, 20Cr, 40Cr ... Mo, 20CrMnMo, 20CrMnTi, 17CrNiMo6, 20CrNi2MoStandard of pruduction: ISO1328-1995Smelting method: electric arc furnace + refining furnacePrecision accuracy: according to GB ... is done according to GB/T231 standardStandard of ultrasonic flaw detectionAll forging pieces must ...