Hi Guys,
I solved the problem. After further investigation I found what the thread tolerance was as far as minimum pitch diameter. I didn't want to just "make it fit" as that is not the correct way to turn a thread. For those of you who do not know...thread wires are a series of wires in sets of three of different diameters for measuring different thread pitches. Best wire size is calculated for a particular thread pitch. A micrometer reading is made over the thread wires and the pitch diameter (where the wires contact the thread) is calculated from that measurement. Of course this does not resolve the possibility of incorrect or variable feed rates over the length of the thread but is still the best way (other than thread ring gages) of measuring an od thread.

Thanks for your input..

Geoff:dance: