... .N-80,J-55 and K-55 P-110 2.Casing joining coupling and tubing coupling 3.STC.LTC ... toolsOur company manufactures and sells casing and tubing couplings,pup joints, tool joints, adapter pup-joints, adapter couplings, stabilizers, ... BTC,LTC,STC.Size of Tubing , 2 3/8 " - 4 1/2"Outside diamete, 60.32 – 114.3mmWall ... .83-6.88 mmEUE,NUESize of Casing ,4 1/2 "- 20."Outside diameter ,114.3 - 508mmWall thickness, ...