Detailed Product Description Tubing and CasingAPI SPEC 5CT, API SPEC 5B ,OD:38mm- 406mm (1inch-16inch) WT:3.5mm-100mm Tubing is used to extracting petroleum and natrual gas from a well. Casing serves as walls of a well.ODWTinmm inmm1.900"1.948.260.1253.181.948.260.1453.681.948.260.25.082 3/8"2.37560.320.1674.242.37560.320.194.832.37560.320.2546.452.37560.320.2597.492.37560.320.3368.532 7/8"2. ...