Abstract: Among the OCTG pipes,the drill pipe is required to be suitable for the most critical service conditions,and with the most satisfactory operation performance and the highest quality.Thanks to continuous studies on related manufacturing processes such as steelmaking,upsetting,heart treatment,straightening and friction welding,and so on as conducted by Baosteel,the key technical parameters which affect the quality of the drill pipe are improved and enhanced,including the steel cleanness,and the length in Miu of internal upset transitional area,toughness and straightness of the pipe.As a result,the drill pipes produced by Baosteel have met the urgent demand for such products to cope with the increasingly developed oil well-drilling technologies.