... industries, such as drill pipe, petroleum oil pipe, oil and natural gas and so on. Seamless steel ingot is made of perforated ... hot-rolled, cold-rolled or cold call is made. Seamless steel pipe with a hollow cross section, a large number of ... for wellbore casing.LinepipeA,B,X42,X46,X52,X56,X60,X65,X70,X80 API SPEC 5L,GB/T9711.1,GB/ ... , water and oil in the short-distance transport. Seamless steel Pipe