... , such as drill pipe, petroleum oil pipe, oil and natural gas and so on. Seamless steel ingot is made of perforated ... pipe, petroleum oil pipe, oil and natural gas and so on.Product NameGradeStandardVisual and Dimensional ApplicationCasing and TubingJ55,K55,N80,L80,C90,C95 ... T9711.1,GB/T9711.232-1240*3-100For oil and gas industry, oxygen, water and oil in the short-distance transport. Seamless steel ...