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I am attaching a cable management tray to the underside of my solid wood desk (acacia). I heard about threaded inserts which are good for when you want to disassemble things frequently. That sounded like a good idea since I plan on moving in the near future and it would be easier to remove the tray from the desk.

So I got a set of threaded inserts and watched some videos showing how you can use a long screw and nut locked up against the insert and then easily drive in the threaded insert with a drill. Here is one of the videos I watched.

However when I tried it the threaded insert went in diagonally and now I don't know how to remove it (see photos below). I tried putting the drill in reverse but it just causes the screw and nut to come out even after tightening the nut to the insert as much as I can. How can I remove the threaded insert? Keep in mind I have a bunch of extra inserts so I don't care what happens to the insert, I just want minimal damage to the desk.

threaded insert inserted diagonally threaded insert inserted diagonally with bolt and nut

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  • Areas for improvement: Don't use the insert upside down (even if the video procedure was a good idea, which it isn't, and even if it was successful, you still would be able to remove it if it wasn't upside down), don't use an impact driver through a lock nut (I find that ridiculous, the lock nut will absorb the impacts and may have contributed to sending it the wrong way), don't use an impact driver on furniture, don't use a needlessly long extension to start any screw. Look for "how to do it right" videos, not "how to hack it" ones.
    – jay613
    Apr 1, 2023 at 12:57
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    For one or two removals, ordinary woodscrews will be fine. I suggest using Torx ones. All you need to do for reassembly is turn the screw backwards until you feel it drop into the thread that is already there, then screw in as normal. There's no need to tighten it as hard as you can, just enough to, say, lift a mobile phone from one end with your fingertips. Apr 1, 2023 at 20:09

4 Answers 4

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One thing to try is to grab the insert with a vice-grip (or similar) locking pliers. If you can get a good enough grip, you may be able to work it out.

Otherwise, you can try using a Dremel (or similar) rotary tool with a metal cutting wheel to cut a slot in the top of the insert so you can use a large flat-head (slot) screwdriver to rotate it. One danger here is that you may slip off the insert and mar the wood surface.

In fact, if you examine the inserts, you will probably find that the other end already has a slot. In the future, use that as the top so that you can use the screwdriver to work it out.

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    Thanks, good idea with the Dremel. I'll try that since I don't have locking pliers. About the slot, I definitely kicked myself for not doing it that way. Some of the videos I saw recommended putting the slot end first to make it look cleaner Mar 31, 2023 at 19:36
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    Otherwise get some Loctite- the strongest grade- which will allow you to lock the internal screw in place so that you can remove both the screw and insert. Apropos the slot, if this is shallow (1-2mm) it's for a screwdriver and should be at the open end, while if it is deeper and the insert looks slightly reduced it should be at the closed end since it will be opened up by the screw locking the insert into place. Apr 1, 2023 at 6:00
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Easy work for a vice grips, you'll own it for a lifetime.

"Use a power tool" was terrible advice. Unfortunately some younger people feel a need to always use a power tool. This fails to teach them the tactile feel of how tools and materials work. As you discovered, power tools are also extremely uncontrollable, in two ways:

  • things happen far too fast to react to things going wrong.
  • it's not safe to hold or steady the tool or work.

I would have had my fingers wrapped around the point where driver meets bolt, to keep the thing dead nuts vertical. Obviously that would be a good way to skin fingers with a power drill, so I would use a hand screwdriver or ratchet. A drill is the wrong speed and torque for that job anyway, but you'd know that from learning materials.

If in doubt, use a hand tool. Generally I go to power tools when I'm about to get Popeye arms from using hand tools, and by then I have a feel for the material, obviously.

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  • I think you are spot on. While I was trying to tighten the nut onto the threaded insert to be able to remove it, I noticed I was starting to drive the threaded insert into the wood with just a wrench. So I inserted the rest of the inserts with just a wrench. Unfortunately every resource I found suggested nothing other than a power tool to do the job. Apr 1, 2023 at 15:30
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Put an adhesive (think threadlocker) on the screw and make the screw-nut-insert one piece. Then the reverse drive on the screw will remove the assembly.

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If you don't care about damaging the insert:

Added to wikipedia by Bushytails - CC BY-SA 3.0

(Picture by Bushytails @ Wikipedia - CC BY-SA 3.0)

Screw extractors are likely to destroy the inner threads, but should make it a breeze to get the insert out. They are typically cheap, and a set of five sizes can commonly be picked up for ~5USD.

Do not use a power tool on the extractor. Turn it using a wrench or other hand tool. Using a power tool will break the extractor, and now you'll be left with a broken, hardened and brittle extractor inside the screw.

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  • My immediate thought too. But unscrew by hand, not a power drill in reverse. +1.
    – Tim
    Apr 1, 2023 at 10:52
  • Good point. Powertools tend to leave you with two problems: the stuck bolt and a hardened, broken extractor
    – vidarlo
    Apr 1, 2023 at 11:55
  • It's only in wood. Trying to use a screw extractor for that case is likely to be more work than just using (locking) pliers. Apr 1, 2023 at 20:05
  • @AndrewMorton There's no kill like overkill ;)
    – vidarlo
    Apr 2, 2023 at 0:57

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