Mysterious Plug Pin Holes, We're Being Lied To!

Maybe lie is a strong word and I have no evidence of an intentional lie, but I'm also not discounting deception either. Google search makes a statement as if the notion were fact, but actually, the claim is proven not to be true. We want the hole truth with no gaps!

Our whole lives we have lived with holes in the pin (or blade) of electrical plugs, but what is the history?

What are 'they' hiding?

Who knows their purpose?

Tests, answers, and even more questions here:

a reply to: saint4God
Most antique lamps/electronics that have original plugs have no holes in the plugs. I had one recently. I am going to watch this video though as now I am curious why the holes appeared.
Ok watched it. The holes are strictly optional and for efficient manufacturing purposes only. I had a feeling, but thanks for confirming it.

a reply to: saint4God
Is this an American thing? I'm on the other side of the Atlantic, and I've never seen anything like that picture.

originally posted by: DISRAELI
a reply to: saint4God
Is this an American thing? I'm on the other side of the Atlantic, and I've never seen anything like that picture.

Yes! Plugs with holes is ridiculously American. I remember visiting England in 2006 and needing adapter kits for all my goofy devices. This wasn't a difficult transition. Driving on the opposite side of the road and car however was a very different story.

originally posted by: worldstarcountry
a reply to: saint4God
Most antique lamps/electronics that have original plugs have no holes in the plugs. I had one recently. I am going to watch this video though as now I am curious why the holes appeared.
Ok watched it. The holes are strictly optional and for efficient manufacturing purposes only. I had a feeling, but thanks for confirming it.

The holes also function as detent locks to help keep the plug, plugged.

Antique radios liked to use resistor power cords and were aptly nicknamed "curtain burners". I suppose a side effect of not having the holes, is one probably wanted the plug to fall out if someone wasn't in the room watching for fire!

originally posted by: Ravenwatcher

Mister Busey makes a number of excellent inquiries. I had not really considered wienerwurst lubricated by churned cream before. Perhaps each topic could be a thread? Best to focus on one topic at a time or else the scope of the investigation may consume so many resources that we're unable to reach any of the conclusions for the answers we seek.

Although I don't typically observe extra-purview anomalies, to be fair to me, Above Top Secret is a forum to explore strange and unexplained occurrences...so I am sticking to societal influence as my excuse.

a reply to: DISRAELI

The real mystery is why in the U.K. we have 3 pins and an extra wire we call earth/ground when other countries just use the negative wire as ground?

originally posted by: surfer_soul
a reply to: DISRAELI

The real mystery is why in the U.K. we have 3 pins and an extra wire we call earth/ground when other countries just use the negative wire as ground?

elf and safety innit?

I think the whole ground thing is rather overlooked these days as electronics seem to break down less, but thats the point of the earth, to be there when stuff breaks.

originally posted by: gb540
The holes also function as detent locks to help keep the plug, plugged.

Antique radios liked to use resistor power cords and were aptly nicknamed "curtain burners". I suppose a side effect of not having the holes, is one probably wanted the plug to fall out if someone wasn't in the room watching for fire!

That is the current Google mythology, though the video provides evidence otherwise...but perhaps wasn't always historically the case? Now we need an Electrical Historian...or maybe a Historical Electrician? Preferably an Electrical Historical Hysterical Electrician Historian.

originally posted by: DISRAELI
a reply to: saint4God
Is this an American thing? I'm on the other side of the Atlantic, and I've never seen anything like that picture.

Dis, believe me, the feeling is mutual when an American sees a British "mains connection" for the first time

Cheers

originally posted by: F2d5thCavv2

originally posted by: DISRAELI
a reply to: saint4God
Is this an American thing? I'm on the other side of the Atlantic, and I've never seen anything like that picture.

Dis, believe me, the feeling is mutual when an American sees a British "mains connection" for the first time

Cheers

Seeing them is way better than treading on them in bare feet in the middle of the night

First the holes. They are to put a locking device in so it cannot be plugged in. I have never seen one and I used a can type safety device that covered the whole thing but they are said to exist at least at one time. The holes can be used to tie safety labels to the plug but I don't consider that effective.

You also find similar holes in circuit breakers that locking devices fit into. These are in common use in industrial and commercial environments.

The ground wire. It is still in common use in the US. It used to be more important as small appliances in the past had more exposed metal. The prolific use of plastic for appliance cases has mostly eliminated the risk of shock from a short to the case.

The term double insulated applies to this. It means the case is not grounded to the neutrial. In the past with metal appliances and power tools, it was possible to have a hot case. If the wiring was miswired backwards, instead of the case being grounded, it was connected to the hot wire. If two tools or appliances, one correct and one miswired, came into contact with a person, it was just like coming into contact with two bare wires. This was also a problem around orher grounded metal like plumbing.

I hope this helped. I also know knobs and tubes wiring, American telegraph equipment and other such mostly useless information.

Id have guessed those holes were to locate sprung bearings in making it less likely that the plug just falls out of the socket

a reply to: saint4God

The maintenance guys at work tie labels to the holes so when you go to plug it in to use it the label cannot be ignored. On larger equipment (7" grinders, small drill presses, circular saws, etc) they lock out the plug, I've also seen them directly wire power using the holes I'm guess for a good connection.

I think they were intended to have a safety purpose in mind, a small bump inside the plug to hold the plug in place, but electricians have found other uses for them and it's become an industry norm.

a reply to: SprocketUK

That would possibly cause a fire hazard. If the bearing and spring was the only contact area in a worn out recepticle it would not be able to carry the current. This would cause the spring to become a heating element.

a reply to: beyondknowledge2

Its hard to put over the design just in words, I saw each leg of the plug pushing down a sleeve of metal carrying the current, at the end of which was the ball arrangement.

I found this on the net and it makes sense:

Some electrical devices also come "factory-sealed" or "locked-out" by the manufacturer with a plastic tie inserted through one or both of the prong holes. Construction projects or industrial safety requirements may call for this type of sealing. For example, a manufacturer might apply a plastic band through the hole and attach it to a tag that says, "You must do 'X' before plugging in this device." The user cannot plug in the device without removing the tag, so they are sure to see the instructions.


There may also be a small savings in raw materials (metal) for the manufacturer of the actual plug prong.

ETA: I have NEVER seen a lock on a plug but many times on outlets, especially in a commercial setting. But it could be a thing

a reply to: saint4God

This Guy ....

youtu.be...

a reply to: strongfp

They are not for lockout or else there would be locks that fit through the holes. I work quite a bit with Lock Out Tag Out and we have a hinged cover we put over the plug of a device to lock it out.

www.mcmaster.com...