API · API 5CT

API Spec 5CT: Technical Requirements for Casing and Tubing

API Spec 5CT Technical Standards: Overview and Scope

The international API Spec 5CT standard defines strict technical conditions for the production and supply of steel casing and tubing, as well as coupling and fitting blanks. At EV Group China, we strictly adhere to PSL-1, PSL-2, and PSL-3 quality level regulations, where PSL-1 serves as the basic industry requirement for the integrity of metal products.

Specifications for PSL-2 and PSL-3 levels, applicable to all strength grades (with the exception of H40, L80 9Cr, and C110), are detailed in Annex H of the standard. When ordering products from EV Group China, geometric parameters, mass, wall thickness tolerances, as well as strength classification and pipe end types comply with Tables C.1, C.2, E.1, and E.2. Upon individual request, it is possible to supply non-threaded pipes with non-standard dimensional characteristics.

EV Group China provides products compatible with connections according to the API Spec 5B standard:

  • Casing with short round thread (SC);
  • Casing with long round thread (LC);
  • Casing with buttress thread (BC);
  • Non-upset tubing (NU);
  • External upset tubing (EU);
  • Integral joint tubing (IJ).

We guarantee full compliance with requirements for coupling products and anti-corrosion protection of threaded areas. For connections with a higher sealing class, additional options are available according to Annex A.11 SR22. We also work with tubular products equipped with specialized connections that fall outside the standard API specifications.

Product classification by strength group at EV Group China:

  • Group 1: Casing and tubing of grades H, J, K, N, and R;
  • Group 2: Casing and tubing of grades C, L, M, and T;
  • Group 3: Casing and tubing of grade P;
  • Group 4: Casing of grade Q.

For casing with diameters from 4-1/2 to 10-3/4 inches, it is possible to use them as tubing (according to Tables C.1, C.23, C.27, C.28 or E.1, E.23, E.27, E.28). At EV Group China, you can order an expanded range of services, including non-destructive testing, impact toughness testing, sulfide stress cracking resistance, and certification according to the extended requirements of Annex A.

Note: Thread connection parameters and metrological control of tools are defined in the API Spec 5B standard.