API Tubing and Casing Coupling 1.Grade: J55, K55, N80, L80, P110 2.Thread: EUE,NUE,BTC, 3.Standard: API 5CT 4.Origin: China ... API Tubing and ... by customer’s requestSIZE: Tubing coupling from 1.9” to 4-1/2”, Casing coupling from 4-1/2” to 13-3/8”TYPE: NUE ...