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I'm looking for a way of removing a sheared-off stainless steel woodscrew embedded in a hardwood plank that is accessible only via a 5.5mm diameter circular hole in a metal panel.

enter image description here

The screw is secured fast, so will need a good amount of torque to remove. The hole is too small for needle-nose pliers and the metal panel can't be removed without a lot of effort.

Because the exposed part of the shaft is mangled at the top, I've thought about several possibilities:

  1. A female square/hex key narrow enough to fit into the hole.
  2. A square/rectangular cross-section metal tube that I can fasten over the exposed shaft.

However, short of going bespoke, I'm not aware of any standardized tools/materials like this.

I'd be grateful for any advice on how I can get it out, short of drilling it.

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  • Have you tried a bolt extractor? If you can find one that is small enough in diameter to fit in the hole it might do the job.
    – jwh20
    Jan 20, 2020 at 11:02
  • I've thought about drilling something into the shaft. But I think the metal is too soft (A2 stainless steel) and the thread too narrow to support the torque needed to twist it out.
    – Brybeck
    Jan 20, 2020 at 11:45
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    I was thinking the EXTERNAL type of extractor where the teeth grab onto the outside of the bolt vs. an internal type.
    – jwh20
    Jan 20, 2020 at 12:25
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    You might describe the larger project context. Maybe removal of the screw from the face isn't the right solution.
    – isherwood
    Jan 20, 2020 at 14:10
  • @insherwood It's a hinge screw for an internal door. But for various reasons I would like to avoid removing the other fasteners from the same hinge plate.
    – Brybeck
    Jan 20, 2020 at 14:35

5 Answers 5

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A quick update on this question that I asked several days ago.

The way of removing a sheared screw like this is by attaching a tubular diamond drill bit (for drilling into tiles, as in the image below) to a power drill. The internal diameter of the drill bit should match the diameter of the shaft of the screw, so that it fits tightly. In this case, a 3mm internal-diameter drill bit.

enter image description here

If the drill is spun in reverse direction while forward pressure is applied, the diamond encrusted tip of the drill bit bites into the screw thread in counter-clockwise direction, turning the screw.

The more tightly the screw is embedded, the more forward pressure may be needed to turn it.

If the first attempt fails, and you just end up cutting away the thread, leaving just the shaft, using a smaller-diameter drill bit (just enough to bite into the outer circumference of the shaft) may work.

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  • Very creative solution and thanks for coming back to post!
    – FreeMan
    Feb 6, 2020 at 13:13
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You could try taking a dowel rod that fits in the hole and drilling a 2 mm hole in the end of it. Put some epoxy in the hole you just drilled and then screw the dowel rod down onto the shank of the screw in the hole. Wait for the epoxy to harden and then try to "unscrew" the dowel rod from the hole backing the screw out with it. I know you don't want to remove the other screws but that might be the easiest. Then you could enlarge the wood hole enough to use needle nose pliers to remove the screw and then reassemble the hinge plate.

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    Not a bad thought, but with ~1mm of clearance you probably aren't going to see the wood hold up to the torque.
    – isherwood
    Jan 20, 2020 at 17:03
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    This is an intriguing idea. Instead of a wood dowel, how about a metal tube or sleeve such as a spacer?
    – Greg Hill
    Jan 20, 2020 at 17:22
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    @GregHill I thought about copper tubing and then heating it up and filling it with solder.
    – JACK
    Jan 20, 2020 at 17:26
  • Solder will stick to copper very nicely, but I'm doubtful it will bond to the stainless steel screw. Maybe so, if the right alloy is used (a silver-based plumbing or jewelry solder instead of tin-lead electronics solder, for example). Still, even if the solder doesn't stick, it does have properties different to epoxy and could be worth trying.
    – Greg Hill
    Jan 20, 2020 at 17:39
  • I would think that sticking something epoxy-coated into a hole this tiny would have a high probability of epoxying the something into the hole, thus making the problem worse.
    – FreeMan
    Feb 6, 2020 at 13:12
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I've had occasional success with a left-hand drill bit. If the sheared end of the screw is relatively flat, or if you can get a small grinder into the hole to make it flat, then you could try this. It might be necessary to construct some kind of aid (a block on the surface, a tube going into the boss, etc) to keep the bit centered on the screw.

A left hand drill bit is so named because it has a left-hand, or reverse, cutting direction. You'd run a drill in reverse to make the bit cut. This way the force of the drill cutting away the screw metal acts to unwind the screw at the same time. In the worst case you end up removing all the screw metal by drilling; in the best case, the drill causes the screw to twist out early.

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  • I've actually tried cutting a groove into the sheared end, so that I could use a narrow flat head screwdriver to turn it. That rotated it by about 5 degrees then broke off the metal around the groove. I think the the shaft is too narrow to support the torque needed to drill it out that way.
    – Brybeck
    Jan 20, 2020 at 18:02
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I think the easiest solution would be to remove the plate, use a hole saw to remove the screw and the wood around the screw, and then plug the hole after with a dowel and glue.

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The fact that its Stainless Steel means that you applied an extreme amount of torque before it snapped... hence that guys is in strong!..

solutions are not going to be easy.. Some possible options

  1. HEAT: if there is a way to get a small blowtorch flame onto the base of the screw , you could heat the screw and singe the wood around the contact points of the screw.. that would at least loosen the "grip" ready to use one of the proposed solutions
  2. REAR ACCESS: if you can get access to the back of the board, you could use a grip plyers to turn it out from the back.
  3. Bend the Shaft: If there were a way to bend the shaft, you could make some contraption to get leverage to twist it out.
  4. some sort of reverse drilling technique: as proposed with diamond head bits or screw removal tools, but being stanless steel, your device must be hard.
  5. Welding: if you can weld.. you can simply weld an adapter to the expose head and turn out
  6. Removal of a block of wood: Use a hole saw and remove the entire area, then replace hole with a dowel stick.
  7. drill a second hole: and patch up this leaving it for ever in the wood.
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