A short length of pipe used to connect two joints of casing or tubing. A casing or tubing coupling has internal threads (female threadform) machined to match the external threads (male threadform) of the long joints of casing. The two joints of casing are threaded into opposite ends of the casing coupling.
| Specification range | |
| OD | 42.16 MM - 508 MM(1.66"--20") |
| Materials | H40, J55, K55, N80-1, N80-Q, L80-1,L80-9Cr, L80-13Cr, P110, Q125 |
| Executive standards | API 5CT, GB, ISO11960, GOST |
| Thread connection | EUE, NUE, STC, LTC, BTC and Premium connection |
| Testing | NDT etc related rules of API 5CT and 5B |
| Type | seamless |
