... " Grade J55, K55, N80, L80-1, L80-9Cr, L80-13Cr, C90, T95, P110, P110-13Cr, Q125, V150J55, N80, L80-1, L80 ... -9Cr, L80-13Cr , C90, T95, P110, Q125 API Connections Round thread(8tpi, STC and LTC), Buttress thread ... nitriding coating; Vacuum insulated; HDPE liner Casing and Tubing in API Spec 5CT