Actually i was more thanking for the input, I learn something new about using ug_convert. I didn't use ug_convert to solve this problem, the problem was that in our company NX3 is connected with IMAN, and on iman there's an option to switch form metric to inches, and during the installation of NX3, my settings of inches was changed to metric. So i was able to work with inches, but still have my part in metric.