... hot rolling size than high precision.Generally with the seamless steel tube: is 10, 20, with 30, 35, high quality carbon steel 45 ... and 16 Mn, 5 MnV and low alloy steel and or 40 Cr, 30 CrMnSi ... , such as auto, the stress of the tractor parts. Generally with the seamless steel tube to ensure the strength and flattened ...