# EMT compression connectors vs. set-screw connectors



## Sparkee (Sep 22, 2009)

I usually use compression connectors when I run EMT since that was what I was taught Industrial Electricians are supposed to do. I have several long runs of 2" EMT that will be in a tight space and it may be difficult to get a wrench on the conduit, not impossible but it will be tight. Can I use set screw connectors? It will be run inside the building and not in a wet environment.


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## 99cents (Aug 20, 2012)

Yes.


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## HARRY304E (Sep 15, 2010)

Sparkee said:


> I usually use compression connectors when I run EMT since that was what I was taught Industrial Electricians are supposed to do. I have several long runs of 2" EMT that will be in a tight space and it may be difficult to get a wrench on the conduit, not impossible but it will be tight. Can I use set screw connectors? It will be run inside the building and not in a wet environment.


Yes, and use the steel ones they look better.


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## don_resqcapt19 (Jul 18, 2010)

There are no issues with set screw connectors other than the jobs specs, wet locations, and the fact that if the conduit run is of any length and you intend to use a vacuum fish tape system, you need to tape the couplings as you go to prevent air leakage when using the vacuum.


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## CTshockhazard (Aug 28, 2009)

I'd use set screw connectors, but if you go the compression route invest in some strap wrenches, they work well in tight spaces.


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## five.five-six (Apr 9, 2013)

I would like to point out that not all compression couplings are raintight, most of them are not. I have never had a problem sucking a mouse through a set screw system caused by air leakage at the couplings.


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## Jlarson (Jun 28, 2009)

Steel set screws are the best connector.


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## Moonshot180 (Apr 1, 2012)

the die cast set screw connectors/couplings like will crack if you dare tighten them down too much..


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## dcb_minded (May 19, 2014)

And if you "hang" anything from the end of the pipe, you need compression

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## don_resqcapt19 (Jul 18, 2010)

dcb_minded said:


> And if you "hang" anything from the end of the pipe, you need compression
> 
> Sent from my SGH-T599 using Tapatalk


Code section?


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## ponyboy (Nov 18, 2012)

I vary between die cast set screw and die cast compression depending on what plant I'm in. I use Bridgeport for everything. I've never had any problem pulling or pushing a mouse through 2"+ emt that had set screw fittings, taping them is just stupid. I put a couple thousand feet of 2" under a conveyor earlier this year and used die cast compression, channellock 440s are more than adequate for wrenching those tight. I agree with jlarson that steel set screw is probably the best bang for your buck but they're hard on bits and I've found the fitting has more play in it than set screw in the larger sizes which can queer your pipes up


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## KGN742003 (Apr 23, 2012)

ponyboy said:


> I vary between die cast set screw and die cast compression depending on what plant I'm in. I use Bridgeport for everything. I've never had any problem pulling or pushing a mouse through 2"+ emt that had set screw fittings, taping them is just stupid. I put a couple thousand feet of 2" under a conveyor earlier this year and used die cast compression, channellock 440s are more than adequate for wrenching those tight. I agree with jlarson that steel set screw is probably the best bang for your buck but they're hard on bits and I've found the fitting has more play in it than set screw in the larger sizes which can queer your pipes up



Most of the larger sizes are for rigid and emt and egg out a bit when used with emt. For what it's worth I have had problems blowing a string in 4" with set screw fittings, so it is a thing.


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## Going_Commando (Oct 1, 2011)

Jlarson said:


> Steel set screws are the best connector.


That is my general attitude.


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## drumnut08 (Sep 23, 2012)

dcb_minded said:


> And if you "hang" anything from the end of the pipe, you need compression Sent from my SGH-T599 using Tapatalk


. You shouldn't be hanging anything( exit sign ) from an EMT drop , and I'm pretty confident it's not legal . This is what rigid and IMC are for .


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## ponyboy (Nov 18, 2012)

KGN742003 said:


> Most of the larger sizes are for rigid and emt and egg out a bit when used with emt. For what it's worth I have had problems blowing a string in 4" with set screw fittings, so it is a thing.


If it's going to be a possible issue I hook up to a jackhammer compressor and blow it through. 180 psi doesn't care what the fittings are


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## drumnut08 (Sep 23, 2012)

don_resqcapt19 said:


> Code section?


. This will be a new one for me too ?


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## Jlarson (Jun 28, 2009)

ponyboy said:


> I vary between die cast set screw and die cast compression depending on what plant I'm in. I use Bridgeport for everything. I've never had any problem pulling or pushing a mouse through 2"+ emt that had set screw fittings, taping them is just stupid. I put a couple thousand feet of 2" under a conveyor earlier this year and used die cast compression, channellock 440s are more than adequate for wrenching those tight. I agree with jlarson that steel set screw is probably the best bang for your buck but they're hard on bits and I've found the fitting has more play in it than set screw in the larger sizes which can queer your pipes up


We buy #2 and #3 phillips and square shockwave bits in bulk :thumbup:


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## Cow (Jan 16, 2008)

A few years back we did a 2" emt run 700' long with set screw fittings and no tape. There was ZERO suction at the other end. We left the vacuum running and went back and started taping couplings. As soon as we heard the bag fly through the pipe we quit taping.



ponyboy said:


> I've never had any problem pulling or pushing a mouse through 2"+ emt that had set screw fittings, *taping them is just stupid*.


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## 99cents (Aug 20, 2012)

ponyboy said:


> If it's going to be a possible issue I hook up to a jackhammer compressor and blow it through. 180 psi doesn't care what the fittings are


I hope you tell your apprentice not to be looking into the end of the pipe when you do that  .


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## dcb_minded (May 19, 2014)

drumnut08 said:


> . You shouldn't be hanging anything( exit sign ) from an EMT drop , and I'm pretty confident it's not legal . This is what rigid and IMC are for .


Digging through the nec now... I know I've had inspectors make us change them to compression... looks as though you are correct... good to know, I've learned something new today. 

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## five.five-six (Apr 9, 2013)

dcb_minded said:


> Digging through the nec now... I know I've had inspectors make us change them to compression... looks as though you are correct... good to know, I've learned something new today.
> 
> Sent from my SGH-T599 using Tapatalk


You should never be supporting a box or device with EMT. 

Just because an inspector let you get away with it doesn't make it right.


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## Southeast Power (Jan 18, 2009)

Jlarson said:


> Steel set screws are the best connector.


if i remember correctly, they are the only type that made it through the last big earthquake in California.

one thing good about compression couplings and connectors if you are doing a demo job,, you can unscrew them 10' away.

Diecast are crap and when i see them it think it was a tight budget job even though diecast was almost double the price of steel not too long ago.


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## five.five-six (Apr 9, 2013)

> jrannis This message is hidden because *jrannis* is on your ignore list.


I'm considering taking you off my ignore list.




Meh. someone will quote you if you said anything worth reading.


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## ponyboy (Nov 18, 2012)

Cow said:


> A few years back we did a 2" emt run 700' long with set screw fittings and no tape. There was ZERO suction at the other end. We left the vacuum running and went back and started taping couplings. As soon as we heard the bag fly through the pipe we quit taping.


I understand your point but at 700' I wouldn't even have attempted to suck a bag through. 700' is the longest straight section in our buildings so I'd probably have a box or at least a C in there somewhere.


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## ponyboy (Nov 18, 2012)

Jlarson said:


> We buy #2 and #3 phillips and square shockwave bits in bulk :thumbup:


You have to with that stuff! I use 6" long Phillips and square bits and if the fittings don't rip the bits right in half they're twisted a quarter turn by days end haha. But they're cheap. Like free


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## Kiknads (Nov 30, 2012)

99cents said:


> I hope you tell your apprentice not to be looking into the end of the pipe when you do that  .


I had a foreman decide it would be a good idea to look into a 4" piece of pvc run underground as the mouse we were blowing through made it to the end. Ultimately, he got soaked, we made fun of him for a bit he went home to change


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