#1 --> I need to cut some 1/4", 5/16", & 3/8" threaded rods
When I do this, the ends get a bit messed up where I cut them
What's the best way to repair the ends - should I bite the bullet and get a tap & die set?
Previously, I've been placing nuts on either side of where I would be cutting, and then using the nuts as a way to sort of repair the threads but I would like a better way.
#2 --> Also, what's the preferred method of cutting these rods?
I originally tried with a thin cutting wheel on my rotary tool. I would suggest the heavy duty cutting wheel, and, if you are going to be cutting the rods to length from a longer piece, I would suggest you have a flexible cable extension to keep the body of the tool out of the way. With the heavy duty wheel and the fact that I was only taking off about 1 inch, I had nice clean threads to deal with. I too was afraid I would have to clean the threads, but, it turns out there was nothing to be worried about.
I use an angle grinder with a super thin cutting disk, most of the time I don’t have to repair the threads, but when I do I use the same method you’re using.
Unless I’m missing something here, I thread a nut on first, make the cut. I clean up the edge with a dremel tool and then unscrew the nut which cleans the threads up.
I do the nut thing as well --add the nut first and remove it to clean-up the threads after the cut. This works, but there is always that little “lip” left after the cut.
What I do is to take the rod, and lay it on a flat table --I use my drill press table, but really, anything flat will work. Lay the rod on the table with the end off of the edge. Simply roll it with the flat of your hand as you run an angle grinder along the “corner”. Hold the grinder at about a 45 or so, and it only takes 2 (very quick) “rolls” to put a nice clean bevel on the end of the rod. I usually use flap-discs for this unless the threaded rod is really a big diameter.
–To be honest, I don’t think a proper die will do any better than just the nut.
The way with the nuts is the most effective and probably the most used one. I learned this already 30 years ago. Cut, file the eges round and remove the nut -> clean and easy.