Tianjin Jinggong Petroleum pipe fitting co., Ltd mainly produces Petroleum tubing and casing coupling. We have 10 modes of tubing coupling and 37 modes of casing coupling, which have 6 steel levels. Main kinds of thread are long round thread casing(LC), short round thread casing(STC) and buttress thread casing(BC). Special-bevel couplings have non-upset tubing(NU) and extend-upset tubing EU. NU has a mode of special â??clearance couplings. EU has two modes of special â??clearance couplings. We have advanced ability of processing and perfect system of quality. We are the designated supplier of Tianjin days Steel Oil Pipe Co., Ltd. for casing coupling and tubing coupling, which products 4 million a year. Our products had all passed the standard test of API Spec 5CT, and get well evaluate based on our high pursuit and tireless efforts of quality. We have advanced technology and complete monitoring tools. Our raw materials were chosen from the suppliers which passed certification of API such as Tianjin Seamless Steel Tube Plant. Our internal control standard which is just less 0.2 times than standard tolerance of API used wet fluorescent magnetic particle inspection equipment for NDT. Coupling thread parameters used Thread single instrument to test. Thread surface used nonstick deduction phosphating solution for phosphatizing. That can make more than 4 times of breakout. All measuring instruments for processing and test are detected by the state-designated agencies in time.Our venture idea is keeping the quality first and the best service. We are constantly improving our products quality and management. We will provide the best products, the highest efficiency service, and build our brand-new international corporate image.We do the effective coordination, oversight and audit on our quality system according to Quality Manual. And we will take the necessary measures when find any phenomenon that against it until the problem be solved