The composition of pipe furnished to this specification, as determined by heat analysis for pipe other than Grade X 80, shall conform to the chemical requirements specified in Table 2, except that by agreement between the purchaser and the manufacturer carbon contents higher than those specified may be used. the composition of intermediate grades(higher than X42)shall conform to chenical requirements agreed upon between the manufacturer and the purchaser, and such requirements shall be consistent with the requirements specified in Table 2 for the applicable type of pipe For Grades X42 and higher, by agreement between the purchaser and the manufacturer, element other than columbium, vanadium, and titanium may be used; however, caution should be exercised in determining the quantity that may be present for any particular size and thickness of pipe because the addition of such otherwise desirable elements may alter the weldability of the pipe.

Line pipe grade designations come from API Spec 5L Specification for Line Pipe. Standard Line Pipe has grade designation A and B. Stronger grades have the designation X followed by the specified minimum yield strength of the pipe steel, measured in kilopounds per square inch (abbreviated ksi), e.g. X60 for pipe having a minimum yield strength of 60 ksi. See the table below for the standard available grades.