... coupling according to API SPEC 5CT AND 5BAPI couplings for oil tubing and casingSize and SpecificationsDescriptions and sizeType of ThreadO.D*L( ... or by requirements of customers Our company manufacture and sell casing and tubing couplings,pup joints, tool joints, adapter ... couplings, stabilizers, air-liquid separators, anchors of oil pumps and revolving sand gravitated device, etc API 5CT tubing ...