Gage STI Before or After Inserted

I get asked frequently: Should I gage the thread after the screw thread insert is installed?

The short answer is: No.

For a more detailed answer I refer you to page 24 or Emhart Teknologies' Heli-Coil Catalog # HC 2000 Rev 1 (02/05) 15M (In case you did not know, Emhart is the company that invented the Screw Thread Insert.):

Accuracy of the finished thread when the insert is installed is dependent upon the accuracy of the tapped hole. If the finished tapped hole gages satisfactorily, the installed insert will be within the thread tolerance. It is not necessary to gage the installed insert. After the insert is installed, the GO thread plug gage may not enter freely; however, the insert will always seat itself when the bolt or screw is installed and tightened.

What more needs to be said?

COMMENTS
Original post date: 9/25/09.
The data provided is accurate to the best of my knowledge as of 9/25/09.
Refer comments/corrections to gageguy@gagecrib.com.