Please note that the API Monogram Program effective date for the this document’s next edition is October 2020. Until then, this edition will still be considered active and not historical.

Specification 7-2 specifies requirements on rotary shouldered connections for use in petroleum and natural gas industries, including dimensional requirements on threads and thread gauges, stipulations on gauging practice, gauge specifications, as well as instruments and methods for inspection of thread connections. These connections are intended primarily for use in drill-string components.

Other supplementary specifications can be agreed between interested parties for special tolerance requirements, qualification, testing, inspection and finishing.

Specification 7-2 is applicable to the following preferred rotary shouldered connection designs:
number (NC) style;
regular (REG) style;
full hole (FH) style.

These are traceable to an internationally supported system of gauges and calibration.

This edition of API Spec 7-2 is the identical (with a few editorial changes) national adoption of ISO 10424-2, Petroleum and natural gas industries-Rotary drilling equipment-Part 2: Threading and gauging of rotary shouldered thread connections. Spec 7-2 replaces threading and gauging previously covered by API Spec 7. This specification contains the API Monogram Annex as part of the U.S. national adoption.