API plain gauges and API thread gauges refer to precision instruments used for measuring the dimensions and characteristics of mechanical parts, particularly in threaded connections. These gauges ensure that parts meet specific tolerances and standards, contributing to the quality and compatibility of components used in oil & gas machinery and industrial processes.
The American Petroleum Institute (A.P.I.) establishes a controlled gaging program to insure API thread form specifications are met in the production of oil field equipment, tools and pipe. A.P.I. requires that those manufacturers using the A.P.I. monogram inspect these components with working gages set to A.P.I. master gages. Our associated API Gauge manufacturing facility is fully licensed by the Institute to use the A.P.I. monogram on all the API Spec 5B, Spec 7-2 and Spec 11B Master gages we sell.
API 5B and API 7–1 are both standards set by the American Petroleum Institute (API) for thread gauges used in the oil and gas industry.
API 5B specifies the dimensions, tolerances, and marking requirements for thread gauges used for the inspection of threaded connections in oilfield equipment such as casing, tubing, and drill pipe. These gauges ensure that the threads meet the required specifications for proper fit and sealing.
API 7–1, on the other hand, is a standard that covers the requirements for rotary drilling equipment, including rotary subs, rotary tables, and drill stem components. It includes specifications for the threads used in these components, ensuring compatibility and proper connection during drilling operations.
In summary, API 5B thread gauges are used for inspecting threaded connections in oilfield equipment, while API 7–1 covers the specifications for thread connections in rotary drilling equipment.