What is the Material of N80 in N80 Casing Pipe? Generally speaking, when you're talking about the material of an N80 casing pipe and 20" API 5L X60 Pipeline, it's usually steel. The material of N80 can be very different depending on what kind of process is used for its manufacture. Some are heat treated, while others are oil quenched. The tensile properties of the steel can vary depending...