How do I thread a galvanized silo rod?

Here's bunch of how to do it videos on threading https://www.youtube.com/results?search_query=DIY+adding+threads+on+glavized+pipes Here's some videos on straightening https://www.youtube.com/results?search_query=DIY+how+to+straighten+galvanized+pipes AS with all online info. you'll need to sort thru these & decide what is right/best way

I do quite a bit of threading with both taps and dies. To straighten the pieces heat them until they are cherry red then tap them down with a ball peen hammer. Make sure not to flatten them as this will make them unusable. Next remove all rust with a wire brush, grinder affixed with a wire wheel, Naval Jelly, etc. then put them in a vise and cut the threads. Some people say to use cutting oil, some don’t. I have never used it and never had a problem and I have literally cut threads hundreds of times. When you are cutting the threads turn the die wrench forward anywhere from a half turn to a full turn then turn it backwards a half turn to break the chip and clear the die.

I think this will be difficult to both straighten them perfectly and thread them, unless you have a lot of free time and a work shop. 5/8” is a #5 which is considered “stout”.

One knows that the galvanized coating is toxic and one wants to avoid breathing the dust or having it their hands.

One also knows that the galvanized coating, once cut, allows rust to form.

I suspect the galvanized coating already has pits.