There are different steel grade types of API spec 5CT casing and tubing: H40, J55, K55, M65, N80 (N80-1, N80Q), L80 (L80-1, L80-9Cr, L80-13Cr), C90 (C90-1, C90-2), T95 , C95, P110, Q125 and so on. H, J, K, N represent general strength oil casing and tubing, C, L, M, T represent limited yield strength oil casing and tubing, which have certain resistance to sulfur corrosion.
In order to distinguish different steel grade strength and thread type, different color codes and symbols are used to represent steel grade and thread of API spec 5CT casing and tubing.
API specification 5CT casing and tubing grades:
| Standard |
Steel Grade |
| API 5CT |
H40 |
J55 |
K55 |
N80 (all types) |
| L80 (all types) |
C90 |
R95 |
T95 |
| P110 |
C110 |
Q125 |
|
In the extreme high temperature and high pressure environment, the API spec 5CT casing and tubing have their own unique natural advantages. API spec 5CT casing and tubing shall be subject to flattening test, tensile test, impact test, tensile test and other related inspection from raw materials to finished products before delivery.
API spec 5CT casing and tubing are mainly used for exploitation of oil, natural gas and other resources. API spec 5CT tubing is used to extract oil or gas from an oil well. While API spec 5CT casing is used as the wall of a well.
