Std Ref.: API 5CT 5B ISO9001, 2008 Grade: J55,K55, N80-1,N80-Q,L80,C90,P110 Size: ... , stabilizers, anchors of oil pumps and revolving sand gravitated device of well, etc. We always do business based on the principle of equality and mutual ... benefit, we provide the high quality and competitive price products.If ...