We produce many various steel couplings and joints of OCTG and line pipes, as well ... , line pipe per API 5L / ASTM A106 / ASTM A53, various steel couplings and joints of OCTG and line pipes, as well ... mechanical products etc. Total annual output is 550,000 pieces coupling (ranging from 1.9"-20", and grades of J, K ... ,000tons OCTG products and line pipes, and other mechanical products. coupling