1.Grade for L-80 .N-80,J-55 and K ... than 10 years experience of producing ,developing and selling oil pipes and their accessories, steel pipe fittings and other ... joints, adapter pup-joints, adapter couplings, stabilizers, anchors of oil pumps and revolving sand gravitated device of well, etc. We ... competitive price products.Have all grade of API standard for thread also.Grade,J/K55,L/N80,P110Thread, BTC ...