# Does anyone use IMC



## Lone Crapshooter (Nov 8, 2008)

Does anyone use IMC? I have run rigid alum and EMT by the mile I have only been on one job that had any IMC and it was sent to another job.


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## ponyboy (Nov 18, 2012)

I've put up plenty of rigid aluminum which is pretty light but never imc. One of our guys transferred here from one of our plants in a different part of the state and he said they used imc everywhere we were using rmc.


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## macmikeman (Jan 23, 2007)

Bout a hundred bales worth bout two and a half decades back. It is tougher than rigid to bend, but cheaper. The specs called for rigid. I got the customer's designer to allow IMC as a substitute and I believe I saved some expense, but I have no historical data to really guarantee that claim.


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## MHElectric (Oct 14, 2011)

I have never been on a job that spec'd IMC.

I have been on jobs where rigid was spec'd, and our PM ordered IMC to cut some corners and save some money.....we never got caught, and they never knew any different.


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## SteveBayshore (Apr 7, 2013)

The original stuff was supose to have a gold tint to it so it would be obvious, I've never worked with it.


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## 347sparky (May 14, 2012)

I have used IMC instead of rigid on several jobs. The only difference I can tell is IMC is harder to thread, sometimes the threads get chewed up when threading.


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## Mich drew (Mar 3, 2013)

We use I.M.C a lot here in factory work. You should use the IMC dies when threading because rigid dies cut the threads to deep.


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## WIREDOG (May 27, 2007)

horse pucky! Stainless is the only threaded conduit that requires special dies the black IMC dies are a scam.


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## Shockdoc (Mar 4, 2010)

One of our SHs was passing it off as RMC after last years hurricane. That's ok except for when it's 2 1/2 " and used on a mast, like I got stuck installing.


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## Shock-Therapy (Oct 4, 2013)

Just roughed in a job with artsy fartsy open framing and used IMC for some of the lighting. A long run from one end of the porch to the other, 40-50 ft or so with 10 boxes in between at various points. Was a pain in the anus. Compression connectors the whole way. Getting that run all lined up and the boxes on plane was enough to make me wanna torture the architect.


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## Shock-Therapy (Oct 4, 2013)

I still might.


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## Fordsnfishin (Dec 16, 2013)

Ran it in a few factories.

Last place we ran it, we only had about a 60 foot run. Was 2'' imc. That soon was switched to rigid. After ruining 2 sticks of that **** we called our GM and asked if we could just use rigid.

With our bender it was causing it to wrinkle on the 90, whether we went slow or fast. Switched to rigid and came out perfect. (yes the shoes were rated for imc or rigid.)


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## TOOL_5150 (Aug 27, 2007)

IMC doesnt bend as smooth as rigid.


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## Southeast Power (Jan 18, 2009)

I like to use it when I don't want to bury PVC 18" below grade.
Otherwise, unless it's specified, Rigid and IMC are completely interchangeable, it's lighter and cheaper and the inside diameter is bigger. I can't see going with Rigid unless you absolutely had to.
Yeah, small learning curve when bending or threading but, just the weight of it makes it worth it.


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## EC2253 (Mar 7, 2008)

IMC is the same type of steel as EMT so its harder tougher to bend, thread and cut, the sidewall is thinner than GRC so its lighter.


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## don_resqcapt19 (Jul 18, 2010)

Mich drew said:


> We use I.M.C a lot here in factory work. You should use the IMC dies when threading because rigid dies cut the threads to deep.


The thread specs for IMC and rigid are identical, although you do have to be very careful to have the die set for the correct depth. Often rigid dies are set deeper than they should be, but if you do that with IMC, you risk the conduit breaking at the threads because of the reduced wall thickness.


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## MWayne (Nov 8, 2010)

I use IMC occasionally and thread it with the same die as galvanized rigid, so far no problems. You might want to reconsider its use in areas of severe corrosion because the inner coating is like on the inside of EMT, here is a pic of some IMC we recently installed:










Rust has already started where the inside coating was not uniformly adequate.


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## noarcflash (Sep 14, 2011)

Take it to a muffler shop with a mandrel pipe bender. Comes out perfect every time. No wrinkles.


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## hardworkingstiff (Jan 22, 2007)

I ran into some rigid (1") that actually damaged my hickey bender. I can't prove it, but it sure seemed like the conduit was made like galv fence posts, kind of stiff compared to the rigid I was used to. I think some of it came from France, and some other came from Mexico. It cost more but I switched to USA made and it was better.

A few years later, even the stuff made it the USA was acting the same way.

I used the 3/4" and 1" sizes (gas stations).


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## Southeast Power (Jan 18, 2009)

I have installed plenty of both and I would choose IMC over Rigid every time unless the specs call out Rigid. I would go as far as requesting a sub and crediting the owner. It's that much better!


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## sbrn33 (Mar 15, 2007)

Shock-Therapy said:


> Just roughed in a job with artsy fartsy open framing and used IMC for some of the lighting. A long run from one end of the porch to the other, 40-50 ft or so with 10 boxes in between at various points. Was a pain in the anus. Compression connectors the whole way. Getting that run all lined up and the boxes on plane was enough to make me wanna torture the architect.


It is not really running IMC when you use threadless connectors.
I actually use it almost anywhere I would normally run GRC. I don't really know why I just do. It's a little lighter and stiffer. I have never used it for a mast but I would have no problem doing it.


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## MDShunk (Jan 7, 2007)

I did a couple warehouse jobs for the same developer that required IMC for anything under 10 feet AFF, and EMT above that. When forklifts are involved, I don't care what you run, they can tear up anything.


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## MTW (Aug 28, 2013)

MDShunk said:


> I did a couple warehouse jobs for the same developer that required IMC for anything under 10 feet AFF, and EMT above that. When forklifts are involved, I don't care what you run, they can tear up anything.


I did some work at a forge in PA with the same requirement.


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## MDShunk (Jan 7, 2007)

MTW said:


> I did some work at a forge in PA with the same requirement.


Seems to be a fairly common spec on jobs that are a bit more 'industrial' than commercial. Biggest issue I had was showing the other guys that if they were gonna hit a box in another few feet, just stick with the IMC and don't bother to change over to EMT for just a few feet. "But, but, but...". :laughing:


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