1.Grade for L-80 .N-80,J-55 and K-55 P-110 2.Casing joining coupling and tubing coupling 3.STC.LTC ... other down well toolsOur company manufactures and sells casing and tubing couplings,pup joints, tool joints, adapter pup-joints, adapter couplings, stabilizers ... .Size of Tubing , 2 3/8 " - 4 1/2"Outside diamete, 60.32 – 114.3mmWall thickness,4.83-6.88 mmEUE,NUESize of Casing ,4 1/2 "- 20."Outside ...