Drill Pipe Steel Strength

The steel grade of the drill pipe refers to the grade of the steel of the drill pipe, which is determined by the yield strength of the steel of the drill pipe. API (American Petroleum Institute) classifies drill pipe steel into five grades: D, E, 95(X), 105(G), 135(S). The higher the steel grade of the drill pipe, the greater the yield strength of the pipe, and the greater the various strengths of the drill pipe. In the strength design of the drill string, it is recommended to increase the strength of the drill string by increasing the steel grade, rather than increasing the wall thickness.