OCTG - Coupling for Casing & Tubing

Couplings are short lengths of pipe used to connect 2 joints of tubing or casing. They come with painted colour codes on their external surface to indicate their grades. Couplings are manufactured according to API 5CT and 5B specifications.

API Tubing Coupling:   Specification
Size (Pipe OD) (in)
1.900, 2-3/8, 2-7/8, 3-1/2, 4, 4-1/2
Upset, Non Upset, External Upset
Grade J-55, C-75, L-80, N-80, C-95, P-110
Option Electro-zinc plated, Phosphorised

API Casing Coupling:
Specification
Size (Pipe OD) (in) 4-1/2, 5, 5-1/2, 6-5/8, 7, 7-5/8, 8-5/8, 9-5/8, 10-3/4, 11-3/4, 13-3/8, 16, 18-5/8, 20
Threading Short Round-Thread Casing (STC) Long Round-Thread Casing (LC) Buttress Thread Casing (BC)
Grade H-40, J-55, K-55, C-75, L-80, N-80, C-95, AS-95, P-110, L80-13CR