API 5CT Q125 Pipes

Deep and ultra-deep oil and gas wells can place substantial pressure and collapse loads on casing strings, making high-strength casing essential for demanding well sections. Amardeep Steel supplies API 5CT Q125 casing for applications where its high yield strength is required beyond grades such as API 5CT P110 pipes. For wells requiring sour-service casing, see our API 5CT T95 pipes. We also offer seamless pipes and tubes in various grades and specifications for oilfield and process applications.

Each order is supplied with mill test certificates, Charpy impact test results, and grade colour banding on every length for material identification and traceability.

What Are API 5CT Q125 Pipes?

API 5CT Q125 is the only grade in Group 4 of the specification. It has a yield strength of 862 to 1034 MPa and a minimum tensile strength of 931 MPa. Unlike most API grades, Q125 is made as casing only, not as tubing.

Q125 lets well designers handle the pressure and collapse loads found in very deep wells without moving to extremely heavy walls.

Why Q125 Is Kept for Sweet Wells

At this strength level steel is highly sensitive to sulphide stress cracking, so Q125 is not recommended where hydrogen sulphide is present. Sour deep wells normally use T95 or another restricted yield grade.

API 5CT Q125 Colour Code

Q125 casing is identified by one orange band, and the grade, size, weight and heat number are stencilled on each length.

Heat Treatment of API 5CT Q125 Pipes

All Q125 casing is quenched and tempered along its full length. The tight yield window of 862 to 1034 MPa means quenching and tempering have to be closely controlled on every heat.

Applications of API 5CT Q125 Casing

• Production and intermediate casing in deep and ultra deep sweet wells
• High pressure, high temperature well designs
• Casing strings that face high collapse loads, such as through salt zones
• Offshore deep water wells

Testing and Documentation

Every order of API 5CT Q125 casing 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
• Charpy V-notch impact test
• Hardness variation check through the wall
• 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.