I'm trying to remove the thumb turn on my door. There appears to be a set screw that's preventing the knob from coming off. I believe the manufacturer of the lock is Lawrence Hardware.

I have tried every hex wrench I have (including those in my iFixit kit: https://canada.ifixit.com/products/mako-driver-kit-64-precision-bits). Everything just seems to freely spin.

Does anyone know what type of screw head I'm dealing with here? Is it a security bit of some sort?

Thank you in advance for the help!

Set screw in thumb turn

  • 1
    Unless there is another hole opposite to that, maybe it is a pin, I think the only wrench for removing it is a drill and bit. It might have had a hex socket at one time in the past, but not anymore. If you do not want to use a drill, an epoxy glue might hold a hex key in it long enough to remove. 50/50 chance if you wait till complete set of the glue.
    – crip659
    Mar 27, 2023 at 20:04
  • Thanks for the advice! I may try the epoxy approach..
    – crosswinnd
    Mar 27, 2023 at 20:31
  • I'm sure it's a hex keyed screw. Might be a metric size. Also, I just removed the door know on one of my doors and, though I'm not certain, it may have been reverse threaded. So when I thought I was trying to remove the screw, I was really over tightening it. Luckily I did not destroy the head in the process.
    – SteveSh
    Mar 27, 2023 at 20:44
  • If this is a thumb turn on a deadbolt, why are you removing it? Mar 27, 2023 at 20:49
  • If you do use an epoxy, everything(hole and key) needs to cleaned of all paint/oil/dirt. The hex key will need to be held solid to the hole for maybe hours, before trying, for best results. A drill will take a minute or two. Will depend if this for replacement or repair. If replacement, a nice big hammer sometimes works as well as a drill, but faster.
    – crip659
    Mar 27, 2023 at 21:10

2 Answers 2


I seriously doubt that's a setscrew. More likely it's a spring retainer. Try pressing it in with the tip of a pointed object such as a nail (or one of those hex wrenches); if it moves, hold it depressed while pulling the knob off.


If you think it is a screw (I don't), you can try using a screw extractor tool.


  • Sometimes just the left-rotation drilling will walk the troublesome fastener out, but the extraction component may indeed be needed.
    – fred_dot_u
    Mar 27, 2023 at 20:15
  • Ah interesting! If it isn't a screw, what would it be? I did try an awl with some pressure while pulling outwards on the thumbturn but it didn't seem to do anything either.
    – crosswinnd
    Mar 27, 2023 at 20:27
  • 1
    Looks like a crimp factory made to keep the pieces together and never anticipated to be taken apart. Mar 27, 2023 at 22:08

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