... 1.Grade:J55,K55,N80, L80,P110 2.Thread: STC,LC,BTC 3.Standard: API 4.Place of Origin: China stainless steel ... coupling from 4-1/2” to 13-3/8”TYPE: NUE, EUE (tubing coupling), STC, LC, BTC (casing coupling).SURFACE TREATMENT: ... 88*269.8823.1610-3/4”STC298.45*203.2020.7810-3/4”BTC298.45*269.8825.7411-3/4”STC323.85* ... 203.2022.6411-3/4”BTC323.85* ...