Why Do Electrical Plugs Have Holes ??

[billt460]

This guy goes the long way around the barn to explain this. But his answer makes no sense. At 2:45 in the video he states that, "Companies aren't going to make more money by, "filling those holes in". That makes no sense, because it takes an extra step in manufacturing to install them in the first place. (drilling / stamping). You can't "fill in" what's already there.

By eliminating even a small part of the manufacturing process, it is going to save money. Especially over tens of millions of units, over years of manufacturing. It's an extra, unnecessary step, regardless of how you look at it. He did prove they're not needed. (Nothing in the female plug uses them to achieve greater retention.)

So, why are they needed? This guy did do a pretty good job and explaining why they're not needed. But he failed at answering the very question his video was supposed to answer.

 

[APEowner]

I always assumed that those holes match up with a nib of some sort for retention purposes but I just looked at the NEMA standard and the answer isn't that simple.

The locking configurations use a nib in the receptacle that lines up with the holes in the blades but the standard says this about the holes on non-locking configurations.

"NOTE:
Hole in flat blade is optional, and is intended for manufacturing purposes only. However if used it must be located as per dimensions shown above."

From that I would assume that it's used in the overmold fixturing during manufacturing.

 

[CoogarXR]

Yeah, I keep seeing the click-bait "why do plugs have holes" thing on various sites. It's always interesting to see how fast a simple, mostly meaningless, click-bait topic can spread.

I assumed the holes aren't anything important or universal, since many (especially older) devices don't have them.

 

[MBfreak]

To precisely get the two blades positioned before the injection molding of the insulation takes place
Ola

 

[Bert_]

I just ignore videos with click bait so I definitely didn't watch it. Pretty sure the holes are just to position stuff during manufacturing. Doesn't serve any purpose for the consumer

 

[cybrdyke]

So you can put a padlock on it so that no one plugs in a machine that you might be working on. Just like in the picture.

 

[billt460]

So you can put a padlock on it so that no one plugs in a machine that you might be working on. Just like in the picture.

No. Watch the video.

 

[FMB4]

The holes are not in the "plugs". The holes are in the 'Terminals' of the plug. Such holes could, most likely, be used in the manufacturing process (as MBfreak, and others before, wisely mention). They could also be used to help to clean the contact female contact surfaces whenever the plug is inserted or removed from the receptical. Btw, the video you watched proves absolutely nothing.

 

[quickfarms]

The holes are there to enable hillbilly wiring, you can make extension cords by only using the male end, which is free on the weekly curbside shopping day.

 

[JunkBonds]

The holes are there to enable hillbilly wiring, you can make extension cords by only using the male end, which is free on the weekly curbside shopping day.

Nope....hillbilly wiring is as easy as stripping the wire ends and sticking them in the receptacle. Done it many times in my youth.

 

[cybrdyke]

No. Watch the video.

I did. There's just as many videos that agree with me.

 

[billt460]

I did. There's just as many videos that agree with me.

Then post some of them. I'm not trying to argue with you. I'm trying to get a truthful answer to a question. As I said, that video made some good points why the holes are not there. He just didn't answer the question very well why they are.

 

[Meursault74]

They have holes so that they can be used in religious establishments. See they're already "Holy" right out of the box.

 

[cybrdyke]

Then post some of them. I'm not trying to argue with you. I'm trying to get a truthful answer to a question. As I said, that video made some good points why the holes are not there. He just didn't answer the question very well why they are.

Not inclined to do your research for you, but here's just one of them.

Skip to 5:00.
Just go to youtube and type in "holes in prongs of plugs". Or google the same thing. You'll get lots of hits.
CD

 

[APEowner]

Why are people looking for explanations beyond the one in the NEMA standard which says that they're there for manufacturing purposes?

 

[billt460]

Not inclined to do your research for you, but here's just one of them.

Skip to 5:00.
Just go to youtube and type in "holes in prongs of plugs". Or google the same thing. You'll get lots of hits.
CD

The video I posted stated the holes were there long before "lockout / tagout" became an industry practice. In short, the videos contradict each other.

 

[infinkc]

When the ends wear to the holes it’s time to replace the cord.

 

[SlappyWhite]

You guys know that just because some dude says something on Youtube it is not automatically true and they are not the foremost expert?

As for the holes, there are, as with everything that has been made for ~100 years the original reasons, the no-longer applicable reasons and the modern reasons... All the below can be valid common sense wise:

• First reasons, I am sure no one can say 100% for sure unless they were there in the room at the time... First patent gives some possible clues of the mindset....
• Retention, makes sense and may have been a bigger early factor as modern receptacles don't have an internal nub that fits into them.
• Contact cleaning (inside the outlet) and debris removal, entirely possible.
• Save material, possible but way down the likely list specially originally. They are stamped, the extra hole punch is not costly production wise today but may have been in the beginning so why the extra step.
• Best modern reason, because they have always been there and consumers expect them to be there--this is actually very common for all kinds of things and likely one of the biggest reasons.
• Some manufactures may take advantage of the holes during manufacturing because they are there, but I am sure not all of them do.
• They get used for lockout, but that is because they are there, not the original reason they are there and for sure not even the main reason. But if that was the only/main reason why have them on a computer or TV power cord, the cord can just be swapped to defeat the lockout, even extension cords...!
• BTW I have seen quite a few plugs without them, CSA and UL gear. BUT they look weird and that can impact sales but there existence partially invalidates much of the above.

Because it has always been done that way is extremely common for all kinds of things.

 

[danfromsyr]

the holes on many are threaded.
will accept a small screw and ring terminal so you ca get 'creative' with wiring.

 

[nh_yota]

The holes started because of the material shortages during WWII and just stayed that way.

 

[SlappyWhite]

The holes started because of the material shortages during WWII and just stayed that way.

The holes predate WW2.

 

[nh_yota]

The holes predate WW2.

Fine. WW1.

 

[kelpaso1]

The holes started because of the material shortages during WWII and just stayed that way.

Got proof of that?

 

[nh_yota]

Got proof of that?

Yes. My great-grandfather served in the Spanish-American War with Thomas Edison.

 

[roblouvasz]

Those holes are for locking style receptacles that are on the area 51 UFOs. The plugs used on test equipment were constantly falling out when the UFOs would execute dimensional jumps.

 

[PapasDaLife]

You guys know that just because some dude says something on Youtube it is not automatically true and they are not the foremost expert?

According to YouTube they "factcheck" all content and remove only those videos which may question what they believe to be the truth. It's done to prevent mis-information getting to the common man who can't possibly make they're own decision.

 

[gungatim]

LGR!

 

[SlappyWhite]

According to YouTube they "factcheck" all content and remove only those videos which may question what they believe to be the truth. It's done to prevent mis-information getting to the common man who can't possibly make they're own decision.

That is for fake news or political content.... not for holes in plugs or opinions about the build quality of electric cars. Of course without the sarcasm font maybe that is what you were getting at....

 

[tomtomgt356]

You guys know that just because some dude says something on Youtube it is not automatically true and they are not the foremost expert?

 

[billt460]

If you're the "expert" why then?

 

[PapasDaLife]

That is for fake news or political content.... not for holes in plugs or opinions about the build quality of electric cars. Of course without the sarcasm font maybe that is what you were getting at....

My comment was sarcastic, I was unaware there was a special font for sarcasm. thanks for advising.

 

[Twodawgs]

I have a probably expensive extension cord that has a locking female end. I assume it uses these holes to lock the male in. Have to pull down on the outer ring of the female end to unlock, kinda like quick connect on a hose.

 

[DougMN]

Fine. WW1.

funny

 

[Meursault74]

Yes. My great-grandfather served in the Spanish-American War with Thomas Edison.

Oh, so then you know that Teddy Roosevelt and his Cavalry group the " Rough Riders" adopted that name because they were issued burlap underwear .

 

[bobg03]

To precisely get the two blades positioned before the injection molding of the insulation takes place
Ola

I am pretty sure technology has changed since 1978, but I worked in a cordset manufacturing facility, where cords with plugs of all gauges of wire were made. The bigger ones with holes were attached to the wire strand by the same machine that attached smaller blades without. The molds were interchangable for different product lines that were made, cords for Remington Shavers to Hubbell cords for ship to shore connections. I can't recall any of the girls having to do anything but set the blades in the mold correctly to load them. The bigger they were the harder to load,,,

 

[gungatim]

LGR

 

[billt460]

My starter battery chargers for both of my generators are identical to that... No holes either.

 

[Copymutt]

From my college courses on electrical theory!
You can subscribe to electron flow or hole flow.
Obviously a starter hole is required for hole flow!

 

[SlappyWhite]

From my college courses on electrical theory!
You can subscribe to electron flow or hole flow.
Obviously a starter hole is required for hole flow!

So the holes were required for conventional current flow, when we switched everything to electron flow they were no longer required but they are still there as we expect them to be there...

BTW, I had an old electrical teacher way back in high school and he would always say that he has to teach electron flow but he did not believe in it...

 

[couch67]

whenever I see this thread pop up I think of that Seinfeld episode where George has the high score on a Frogger game, he buys it, and has to hire an electrician to keep it powered up during the move so he doesnt lose the high score. The 'Electrician' keeps referring to an electrical outlet as 'holes'

funny part at 1:25