I hope this is as simple as I think it is. I have a part the calls out the true position of a 5/16-18 ID threaded hole with MMC. I think that the MMC should come off of the minor diameter. Onr of the owners and the QA manager think it should come off of the pitch diameter. Other than the fact we don't have a good way to measure the pitch diameter in house I think they are wrong. What are the prevailing winds on minor or pitch for MMC on a ID threaded hole?
In the ISO 2692 from 2021, the standard about MMR, LMR & RPR I found threaded features mentioned in two chapters.
One time in the introduction and one time in chapter 4.1.1.
In the introduction it is written that
NO rules are defined for threaded features and using it is risky.
In chapter 4.1.1 it is written that the rules from this standard
shall not be applied to threaded features.
In the ISO 2692 from 2021, the standard about MMR, LMR & RPR I found threaded features mentioned in two chapters.
One time in the introduction and one time in chapter 4.1.1.
In the introduction it is written that
NO rules are defined for threaded features and using it is risky.
In chapter 4.1.1 it is written that the rules from this standard
shall not be applied to threaded features.
That honestly just sounds like something forced into the standard because inspectors can't figure out how to measure it. I've seen drawings with MMC on threads, both ISO and ASME for as long as I can remember.
