... J55,K55,L80,N80,P110 etc. 4.Thread:LTC,STC,BTC · API 5CT N80 oil casing pipe 1. Size:OD ... :6-760mm WT:1-30mm2. Grades:N80,J55,K55,L80, ... our own factory.We maily export alloy pipe,carbon pipe,oil casing pipe,etc.we always have large amount of ... Steel Pipe Plants such as TPCO, Hengyang Steel,Baotou Steel , Anshan Steel etc. standard: API SPEC 5CTTubing ...