I don't want to destroy either part since I plan to try to reuse them. I have applied WD40. I tried to use pliers to rotate them (you can see the scratch marks). Nothing. It is like they are welded together. Picture

This is how a normal one looks like enter image description here

  • 1
    Try heating the part, then try to unscrew while still hot.
    – HandyHowie
    Jul 22, 2022 at 9:43
  • 2
    Sometimes WD-40 is not good enough, might need a better penetrating oil. Most basic hand pliers will not have enough bite, a good pair of locking pliers or a pipe wrench will bite into and hold better.
    – crip659
    Jul 22, 2022 at 11:03
  • 3
    WD-40 is for displacing water. It is NOT a penetrating oil. PB-Blaster, Kroil and probably some others are actual penetrating oils. ATF mixed with tolulene is a home-made one.
    – Ecnerwal
    Jul 22, 2022 at 12:34
  • @Ecnerwal I have heard that ATF and acetone is one of the best. Have not heard of toluene.
    – crip659
    Jul 22, 2022 at 16:11
  • I think I've seen various solvents combined with it, as might happen with it being a "home-brew" recipe.
    – Ecnerwal
    Jul 22, 2022 at 17:47

1 Answer 1


I used a rotary tool with cutting disc to go around the point where the screw and threaded insert meet and striped ~1x1 mm of metal all around. That released the screw and it was free to rotate.

  • Thanks for posting your solution. Be sure to accept your answer. You may want to reconsider reusing this insert. Whatever caused it to jam the first time may repeat itself and you may not be able to extract the screw next time around. Also, now that you've cut into the screw or insert, they may not hold together as they did before and it could fail unexpectedly.
    – FreeMan
    Jul 22, 2022 at 11:58
  • In 2 days! The screw thread is 4 mm long and the threads on the insert go all the way down. I used two part epoxy for metal to glue the insert back. The screw has the same number of twists as normal one and I think it will hold. I hope. Jul 22, 2022 at 15:44

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