This part of ISO 10424 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. This part of ISO 10424 is applicable to the following preferred rotary shouldered connection designs: a) number (NC) style; b) regular (REG) style; c) full hole (FH) style. These are traceable to an internationally supported system of gauges and calibration