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?
Here, the MMC is primarily used to allow the use of hard gages (cylindrical pins, not bolts) in order to have some speed in the checking of the part (manual, no CMM).
The minor diameter is used for the MMC (internal thread). I never apply the MMC when checking these requirements in the CMM though. I do it without MMC.
Here, the MMC is primarily used to allow the use of hard gages (cylindrical pins, not bolts) in order to have some speed in the checking of the part (manual, no CMM).
The minor diameter is used for the MMC (internal thread). I never apply the MMC when checking these requirements in the CMM though. I do it without MMC.
