This one fits pipe thread made by Jaw m.f.g. co. Reading. Pa. #2 it does 8 different threads 8 10 12 16 20 27 28 32 just wondering if anyone else in here has used them I know mine is ancient but still works ok I had to do a 2 inch sewer pipe thread  today where the pipe 6 inch nipple went in wall couldn't get out to put in new plugs scared of threads breaking off in side of wall lol so re-did threads with this tool I had not sure if the right tool to use but it worked.

Great tool to have and use, takes patience, and elbow grease!! Sometimes it is the only tool that will work!!

Still sold as a thread file.   A tool that pays for itself over and over.

Jawco is good people to deal with, too.   bought a set of thread files from them a long time ago and they were priced fair and made well. 

I use mine (from my uncle) nowandagain; there are times when it's the only right tool.

Thread files were used during WW2. Here is one I've found.
-Don