API Spec 5B
Specification for Threading, Gauging, and Thread Inspection of Casing, Tubing, and Line Pipe Threads
Standard Overview
Organization: API | Category: Threading
Referenced by 2 API source standard(s):
High-frequency reference: This standard is cited by 2 different API specifications, indicating it is a foundational standard at the industry level.
How to Apply API Spec 5B
Conformity work starts by confirming the exact edition of API Spec 5B required by the contract and identifying any purchaser-specific additions. The product type, material system, dimensions, pressure or temperature rating, manufacturing route, and intended service environment must then be mapped to the clauses that apply. An inspection and test plan should state the sampling frequency, specimen conditioning, calibrated equipment, acceptance criteria, witness points, and rules for retesting before laboratory work begins.
A defensible report records sample identity, batch traceability, the method and edition used, environmental conditions, raw observations, calculations, measurement uncertainty where relevant, deviations, and the final result against each requirement. LEISA uses this evidence chain to help buyers, manufacturers, and engineering companies distinguish a repeatable compliance decision from a simple pass/fail statement. The original publication remains the controlling source whenever a summary conflicts with the standard text.