... 3.Standard: API 4.Place of Origin: China 13 3/8" btc casing coupling -----------------------------------------------------------------------------------------------------------FeaturesGRADE: J55, K55, N80-1, N80- ... /2”, Casing coupling from 4-1/2” to 13-3/8”TYPE: NUE, EUE (tubing coupling), STC, LC, BTC (casing ... 4”BTC323.85*269.8828.0313-3/8”STC365.12*203.2025.6613-3/8”BTC365.12*269.8831.77 API ...