Toggle switches are frequently attached to a mounting surface with a nut that has two indentations on opposite sides.

  • What is this kind of nut called?
  • What kind of tool is good for tightening and loosening this fastener?

I usually use needle nose pliers. They work, but sometimes mar the fastener.

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  • 1
    For the most part, that is a nut, not a bolt. – Passerby Jul 28 '13 at 7:54
  • Nice Taranis, I just got mine, do you need to loosen the two switches to open the radio? TIA – user26854 Jul 28 '13 at 17:40
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    updated to call it a nut instead of a bolt. – Mark Harrison Jan 27 '17 at 22:14
up vote 7 down vote accepted

I've always known them as slot or slotted nuts (a type of castellated nut) although I did come across a reference to switch nuts, which makes sense if they are used to fasten switches.

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  • +1 nice find on the slotted nut wrenches, I remember having seen those as well now you mention the name. They'll be better than the circlip pliers if the OP can find the right size OK. – PeterJ Jul 28 '13 at 11:50
  • @PeterJ Yes, its a blast from the past. ;) – JIm Dearden Jul 28 '13 at 11:57

There are probably a few names but I've often heard them referred to as dress nuts. A search on Digikey using that term shows plenty of fairly similar nuts although they don't appear to have any with the slot at the top:

I'm not sure if specialised tools are available but a pair of circlip pliers from your local hardware store might do the job, they are available in a wide variety of styles and sizes so take the switch along with you to find one that suits. Most have round prongs which you could remove to make things easier.

Circlip pliers

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