I would like to open up this power extension but these strange screws are in the way. I need some way to unscrew this without damaging it. Anyone know what kind of screw this is? What keyword would you search for?


  • 1
    Go to a decent shop and purchase the bit for it.
    – Solar Mike
    Jul 22, 2023 at 9:58
  • 1
    Could also be a rivet
    – Martin
    Jul 22, 2023 at 10:05
  • Maybe mention why you want to open it. CE mark is not recognized in US/Canada as a legal electrical mark, so if there is a problem with the unit, replacement might a better idea.
    – crip659
    Jul 22, 2023 at 13:31
  • Nothing wrong with it. I need to send the cable through a small hole in the wall. So I thought I could disassemble it, feed the cable through and put it back together. Jul 22, 2023 at 14:24
  • 1
    @mindlessgreen Running an appliance cord like that through a wall is distinctly not allowed by the electrical code.
    – Sneftel
    Apr 26 at 11:45

3 Answers 3


Googled "Screw with three slits" and found the name "Tri-Groove Socket", that looks almost like the screws in you picture.


They are classed ss security screws and they come in many shapes. The idea is to keep the consumer out of the boxes/ appliances.

However, any hardware store should have a selection of these bits for a screwdriver. You can find them on sites such as ebay and aliexpress.

  • 1
    And Amazon (as kits of assorted "security" bits), and...
    – keshlam
    Jul 22, 2023 at 15:23

The appropriate screwdriver bit is contained in this set:


The one on the right is what you need. If the three protruding parts are too wide, you should grind away a little bit from them with a small, oval-shaped grinding stone.

The set is also available from sites such as Amazon by searching for "three point screwdriver bit".

  • Link only answers are frowned upon because if the link fails, the answer is useless.
    – JACK
    Apr 25 at 20:22
  • Are you sure that bit will fit the screws in the question? It looks like a lot of grinding away might be needed. Apr 25 at 20:28
  • For me, the diameter of the bits fit perfectly to the holes, but the wings were too wide, so I had to grind them a little. Apr 26 at 9:16

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