... 13 3/82. Pipe-end: STC, LTC, BTC,;3. Steel grade: J55 N80 L80 K55,,,, P110;4. Standard: API Spec 5 ... and inner anti-corrosion coatingCasing, tubing is indispensable in oil drilling and oil industry. My company is in strict accordance with ... detection, ultrasonic inspection, threaded parameter examination, magnetic powder detection test.. drilling field oil tube(API)