boltshardwaremetal-cutting
I have tried hack saw, manual bolt cutters, plasma cutter – all of which mess up the thread and make it tough to get the nut on. What's the best tool for this? Ideally something under $50 or something rentable? I have a lot of rods to cut (need to make about 50 cuts).
The nuts will be put on once and not removed. I can leave one of the ends unfinished so the nuts don't come off, but one end still needs to be pretty so I can get a nut on in the first place.
After cutting the bolt to length, use a stationary grinder instead of a file to clean up your work. With a grinder, it's easy to square up the end of the bolt and apply the chamfer that you want.
Just be careful, especially if the bolt is shorter than the grinder's table. If the bolt is short, use a pair of vice grips to hold the bolt during grinding. And remember that the end of the bolt is going to be very hot after grinding!
Lock nuts and carriage bolts are a bad combination and even worse when trying to use them in material like particle board or MDF.
You could try to use a Tee nut from the monitor side and then simply use a short hex head bolt into the Tee nut.
Best Answer
I'm sorry, the right answer is a hacksaw. It will leave the threads very slightly burred, but that should come off with a wire brush or worst case a file. Your other methods will deform the thread by squeezing or melting, and that is harder to fix.
And run a threading die down it just to be sure.
The thing is, one tends to take for granted how bolts are made. When a nut starts easily on a bolt, that's no accident, the end of the bolt is finished for that effect. If you simply lop off a threaded rod - even if the cut is perfect, like a waterknife - it will still be awkward to start the thread because it hasn't been finished like a bolt.