API Spec 5B 17th Edition Officially Released

On October 7, 2026, API officially released the 17th edition of API Spec 5B, Specification for Threading, Gauging and Thread Inspection of Casing, Tubing, and Line Pipe Threads. The new edition updates the requirements for the threading, gauging, and inspection of threaded pipe connections, and adds provisions for the verification of advanced measurement technologies.

Threaded connections are used to connect line pipe, casing, and tubing, ensuring the normal operation of oil and gas wells and supporting the transportation of energy products throughout the supply chain. Because these connections must achieve precise fit and maintain reliable performance under high loads and severe operating conditions, ensuring thread integrity is critical to the performance of oil and gas wells and pipeline systems. At the same time, reliable threaded connections also help reduce the risk of leakage and failure.

API Spec 5B safeguards thread integrity by establishing uniform requirements for threaded connections. First published in 1939, this specification provides manufacturers, inspectors, and purchasers with a common basis for confirming whether threaded connections meet specified dimensional requirements and acceptance criteria. These requirements help ensure interchangeability between products from different manufacturers and help users build confidence in the consistency of connection performance.

The 17th edition of API Spec 5B was developed through API’s open, consensus-based standards development process. It is a further update based on the 16th edition, published in 2017, and is intended to make inspection requirements easier to implement uniformly. While the 16th edition focused primarily on dimensional conformance, inspection procedures, and the application of traditional gauges, the new edition further incorporates emerging measurement technologies while addressing the ever-increasing performance requirements for oil country tubular goods (OCTG).

 

The main updates in the new edition include:

• New requirements for the verification of optical measurement, laser measurement, and other non-contact thread measurement technologies, to help improve measurement accuracy and repeatability;
• Clarification that when disputes arise over results obtained using alternative measurement technologies, the measurement results of traditional mechanical gauges shall be used as the basis for acceptance or rejection;
• Updated dimensional and tolerance requirements for buttress thread thread-thickness gauges and their calibration standards;
• Removal of outdated quality requirements and provisions relating to obsolete line pipe ring gauges and plug gauges, aligning API Spec 5B with other current API OCTG standards;
• Updated illustrations, including the use of 3D illustrations to show current gauges and thread features;
• Expanded guidance and tables for determining thread ovality and related standoff requirements;
• Further clarification of calibration and record-keeping requirements.

Released alongside the new edition of API Spec 5B is the 6th edition of API RP 5B1, Gauging and Inspection of Casing, Tubing, and Line Pipe Threads, which provides relevant technical guidance and inspection practices to support the implementation of API Spec 5B requirements.

Note: The article originates from the API Beijing Office.