1.Grade for L-80 .N-80,J-55 and K-55 P-110 2.Casing joining coupling and tubing coupling 3.STC.LTC ... API standard for thread also.Grade,J/K55,L/N80,P110Thread, BTC,LTC,STC.Size of Tubing , 2 3/8 " - 4 1/2"Outside ... thickness,4.83-6.88 mmEUE,NUESize of Casing ,4 1/2 "- 20."Outside diameter ,114.3 - 508mmWall thickness, 5.21 – 16 ...