On a similar note regarding NPT plug gages, I have a 1/8-27 MPT L1 gage that was rejected for "Basic Length". The cal cert shows Nominal at 0.16150" and upper tolerance at 0.16150" with an "As Found" value of 0.17807". Clearly this gage exceeds the upper tolerance, and IF the hole had a bottom, I could see how this would be a problem IF the plug wouldn't go in smoothly. The Pitch Diameter is at the bottom end of the tolerance, so the gage will still go in the part being inspected. Can someone help me understand why, even if there was a bottom to a threaded hole, and the gage went all the way in smoothly, this is a problem?
I now have a Cal. Cert. which shows the gage failed calibration, but for our purposes, the gage will tell us whether the threads of the parts being inspected are acceptable. Is there a way "out" of this canumdrum?
Thanks for all your advice and input!