API 5CT L80 Pipes

API 5CT L80 pipes are used as casing and tubing in oil and gas wells where controlled yield strength and hardness are required. The grade includes L80 Type 1, L80 9Cr and L80 13Cr variants for different service conditions. Amardeep Steel supplies L80 casing and tubing for oilfield applications. Compared with API 5CT N80 tubing, L80 has controlled yield strength and hardness requirements that can support applications where sulphide stress cracking resistance is required. For shallow wells and general service, see our API 5CT J55 tubing, while our range of seamless pipes and tubes covers other grades and specifications.

Each shipment includes mill test certificates, hardness results and grade colour banding for material identification and traceability.

What Are API 5CT L80 Pipes?

API 5CT, also published as ISO 11960, is the specification for steel casing and tubing used in oil and gas wells. It sorts grades into four groups. L80 belongs to Group 2, the restricted yield grades, where the standard sets both a minimum and a maximum yield strength along with a maximum hardness.

Casing lines the drilled hole and holds back the surrounding rock, while tubing runs inside the casing and carries oil and gas to the surface. L80 is used for both. It should not be confused with API 5L line pipe, which is meant for pipelines on the surface rather than inside the well.

Why Restricted Yield Matters in Sour Wells

Hydrogen sulphide in a well can cause sulphide stress cracking in steel that is too hard or too strong. By capping yield at 655 MPa and hardness at 23 HRC, L80 Type 1 stays within the range accepted for sour service under NACE MR0175 / ISO 15156. That is the main reason operators choose L80 over N80, even though both start at the same minimum yield.

Types of API 5CT L80: L80-1, L80 9Cr and L80 13Cr

Heat Treatment of API 5CT L80 Pipes

All L80 pipe is quenched and tempered. The standard also sets a minimum tempering temperature so the steel cannot be left too hard.

• L80 Type 1: tempered at 566 degrees Celsius or higher
• L80 9Cr and L80 13Cr: tempered at 593 degrees Celsius or higher

Applications of API 5CT L80 Casing and Tubing

• Production tubing in sour oil and gas wells
• Intermediate and production casing strings
• Sweet gas wells with high carbon dioxide content (L80 13Cr)
• CO2 injection and enhanced oil recovery wells (L80 9Cr and 13Cr)
• Geothermal wells

Testing and Documentation

Every order of API 5CT L80 pipe goes through the checks below at our testing facility or approved third party labs.

• Heat and product chemical analysis
• Tensile test for yield, tensile strength and elongation
• Hardness test across the wall section
• Charpy V-notch impact test
• Hydrostatic test on every length
• Full length drift test
• Ultrasonic or electromagnetic inspection of the pipe body
• Thread gauging, visual and dimensional inspection
• Third party inspection on request

Mill test certificates are issued to EN 10204 3.1, with 3.2 available on request. You can view our approvals on the certificates page.

Packing and Marking

Each length is stencilled with the manufacturer name, API 5CT, size, weight, grade, connection and heat number, and carries the API colour band for its grade. Threads are protected with steel or plastic thread protectors, and pipes are bundled or loaded loose with spacers depending on size. Read more about our packing and despatch process.