Sell API-5CT Casing, Tubing, Coupling. Our factory manufacture Casing, Tubing: According to API SPEC 5CT. Steel grade: J55, K55, L80, N80, C95, P110 O. D. Range Tubing: From 2-3/8"to 4-1/2"(EUE/NU) Casing: From 4-1/2" to 20", Threads: BTC, LTC, STC. Length range: R1, R2, R3 If you interested in our products, feel free to contact with me.