/Program Files/SolidWorks/lang/english/calloutformat.txt is the "HoleWizard Callout Format Definition File". I'm using Toolbox to configure a screw (not a hole). I don't think Toolbox uses this configuration file.
Note: I don't want to make all screws UNF...just some of the time.
Please tell me where you buy shoulder bolts with UNF threads. I have looked for these and so far all I've found are places willing to make them special. None of my local hardware suppliers seem to be able to get them.
If you routinely get such fasteners, the best thing to do is create a derived Toolbox standard for them. Choose `Configure Browser' from the Toolbox pulldown menu, and follow through the [Edit Data] dialogs to make a derived standard from ANSI, and call it Specials or MMCar.
Then you can type over the UNC sizes with some UNF sizes, or add new entries to the bottom of the Shoulder Screws table in your new standard. (they will automatically resort later)
If the threads are not common, you may also need to make matching entries in the threads tables.