How to remove a carriage bolt from a post without damaging thread??

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TheUnicorn

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what is the best way to remove a carriage bolt, from a snug hole in wood, preserving the thread, especially the start of the thread, for reuse. Obviously if you just pound it out with a hammer, you mar the end of the bolt. If you put on a nut and pound it out as far as it will go are you similarly straining the thread?

I'm asking because I tried to do a repair of sorts today, clearing up someone else's mess, I needed to get a nut onto a bolt that had clearly been bashed in and out of the hole, and damaged in the process, as I was cussing the previous effort I wondered exactly how is best to handle bolts for reuse.

Also was wondering about a deburring tool, are they any good for repairing a knackered thread tip

this sort of thing or similar https://www.amazon.co.uk/Yesiidor-E...child=1&keywords=deburr&qid=1614621415&sr=8-9
 
Several questions come to mind, is it rusted into the wood? Must you really reuse that one or just buy new ones?
If it has been really smashed to bits you could cut the last however much of it and put a nut on, you may need just to file the first thread end a little. Then if you can support the wood in the vice you can give it a good wallop, it shouldn’t damage the threads through the nut or is it going to be too short to reuse anyway now, I can’t imagine a situation where it won’t come out with a heavy hammer. Once you get it so that the nut is touching the wood you may have to then use a smaller bolt to drift it through with, or with a protective piece of wood use a prybar from the other side. Ian
 
Are you planning on doing a lot of these ? if it is just a one off then just replace the damaged bolt.
 
I normally leave the nut on to protect the end of the thread, then belt the hell out of it with a hammer. Coach bolts are pretty tough so the thread shouldn't deform enough to cause a problem. You could also put two (or more) nuts on and tighten against each other to save damage to the thread. Another method is to use a bit of hard wood between the hammer and the end of the bolt.
If I damage thread on the end, I give it a run on the grinder.
 
Agree re the nut on bolt -- thread should be OK. especially if you put a wood block in between.

another way if it's a really large bolt is to use a steel drift of slightly smaller diameter than the threads
 
I agree with the above replies but only until there is enough of the bolt head to get a crowbar/tyre lever under it. Use a piece of scrap ply under it to protect the wood.

Another option would be to use a piece of old oak or similar over the bolt and welly that.
 
Are you planning on doing a lot of these ? if it is just a one off then just replace the damaged bolt.
As I say, I was clearing up someone else's mess, basically there was a nut missing, a tried to put one on, it was visablly damaged when I looked closely, he should have put on a new bolt in place, but instead just left it nutless, shoddy to say the least.

Anyway, it just got me thinking about the best way to remove a firm bolt without damaging the thread. I've come to the conclusion that putting a nut on so its flush with the end and then hammering it all out together is the best way
 
Never used one, but it does look useful. Might be useful when cutting threaded rod, quicker than the grinder.
 
Hi Unicorn, if the bolt head is clear of the wood and you have or can rig up a slide hammer with a fork that may work
 
I use punches to remove bolts to avoid any damage and in your case I'd be looking to see why it was tight in the first place , as the sides of the fastener should have clearance, before cleaning the thread leads with either a file or grinder assuming I didn't just throw in a new fresh bolt.
 
Screw a die (or just another nut) on first, so as it recuts the damaged thread once you have got the job moving?
 
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