Why Do Electric Plugs Have Holes?

In this video from Silver Cymbal on YouTube, we get the full story behind the design choice of holes on electric plugs.

Why do electric plugs have holes? You have seen them for years but what do they do? Stop believing the myths & learn what they do for yourself. After receiving multiple comments asking me to answer this question I hope you enjoy this video.

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1 Comment

  1. From Reddit:

    The holes in the prongs (particularly on US/Canadian plugs) can serve a few purposes. The main purpose is to allow the outlet to firmly grip the plug to prevent it from coming lose and falling out of the socket. This works by having little bumpers installed inside the outlet that line up with and fit inside the holes on the prongs. This keeps the prongs secure inside the outlet, but with enough force the plug can still be removed.

    A secondary feature of the holes is that it allows you to wire 120V power directly to the prongs without using a traditional electrical outlet. If you, for some reason, needed to supply power to the appliance via direct wires, these holes would make the job a lot easier by allowing you to connect the wires directly to the prongs.

    Finally, you can apply a bar or locking device through the prongs as a safety feature to prevent a device from being plugged into an outlet (e.g. as a child safety precaution or to prevent people from plugging in a device that is malfunctioning).

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