What’s The Difference Between APT 5CT N-80 And API 5CT L-80 Tubing?

What’s the difference between APT 5CT N-80 and API 5CT L-80 tubing?

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Casing pipes are available in the following materials: H-40, J-55, K-55, N-80, L-80, C-90,T-95 ,P-110, Q-125 according to API 5CT standard,which covers seamless and welded casing tubing pipes for oil and gas transportation. Do you know the difference between APT 5CT N-80 tubing and API 5CT L-80 tubing?

According to API 5CT,casing pipe is applicable in the following grades to make sure that each casing grade is suitable for its intended application.:

Common Application Casing : Grades H, J, K,M, N and R;

Corrosion-Resistant Casing : Grades C, L and T;

Deep Well Casing: Grade P and Grade Q.


API N80Q pipe is a general purpose pipe manufactured to API specification 5CT using a quench and temper process.It can be divided into API 5CT  N80-1 and API 5CT  N80-Q.Both of them are the same in tensile properties but different in the delivery condition and impact performance.

5CT grade N80-1,normalizing delivery condition or when the finishing temperature is higher than the critical temperature Ar3 and tension reducing after air cooling, and can be used for hot rolling for normalizing, impact and nondestructive testing are not required; 5CT grade N80Q must be quenched (quenching and tempering) heat treatment, the impact should be consistent with the provisions of 5CT API, and should be carried out nondestructive inspection.


API 5CT grade L80 tubing usually used in wells with sour (hydrogen sulfide) environments.They can be divided into 5CT grade L80-1,5CT grade L80-9Cr and 5CT grade L80-13Cr. Their mechanical properties and delivery states are the same. The difference is shown in terms of usage, production difficulty and price. 5CT L80-1 pipe is a common type,5CT L80- 9Cr and L80-13Cr are all highly corrosion-resistant tubing, which is difficult to produce and expensive, usually used for heavy corrosion wells.


API N80 Type 1 is a lower cost alternative to standard Quench and Tempered API N80 (walls less than 0.500 inch). Charpy V-notch impact test absorbed energy results meet API SR16 and are lower than quenched-and-tempered N80.Want to buy  APT 5CT N-80 and API 5CT L-80 casing tubing?Contact WORLD IRON&STEEL !