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 my opinion since it is called out to the thread it is for full thread form which is not just the pitch but the complete AME that the thread specification allows.
In my opinion since it is called out to the thread it is for full thread form which is not just the pitch but the complete AME that the thread specification allows.