... Company IntroductionOur company ,funded in 1997, presently is one of biggest enterprises producing double protection sucker rod joint inside China ... and Daqing Oil Field, also having sold into the markets of Europe, Southeast Asia and Middle East. Moreover, our company ... standard. This is API Sucker Rod Coupling, class SM,with large chamfer1)Material: Good alloy steel bar, AISI 51402)Standard: API ...