GRC vs. IMC

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It's thicker, heavier, and takes more of a beating. We have so many places that GRC has been torn up badly from JLGs, cranes, forklifts, etc. that I'd hate to install anything flimsier.
 
mike abbott said:
For what reasons would a customer or a contractor choose the added expense of GRC vs IMC in a factory?
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Just some quick thoughts off the top of my head...


1)GRC has a heavier wall and may offer more protection in ones opinion
2)GRC can be bought in larger sizes than IMC
3).......ummm there maybe something else...
 
Would it not just depend on the enviroment of the install, you could look at it this way, the customer knows what they want or need! :smile:
 
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mike abbott said:
For what reasons would a customer or a contractor choose the added expense of GRC vs IMC in a factory?
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In addition to what others have said, most non-electrically-oriented customers aren't even aware IMC is an available option. I'm not a proponent of the concept, but in many instances you could probably install IMC instead of RMC and they wouldn't know the difference.
 
Smart $ said:
In addition to what others have said, most non-electrically-oriented customers aren't even aware IMC is an available option. I'm not a proponent of the concept, but in many instances you could probably install IMC instead of RMC and they wouldn't know the difference.
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I can tell you around here, there are a lot of electricians who have never heard of IMC, let alone know what it is.
 
IMC isn't made with the best steel.
It is not the best to try to thread.

I would pick GRC over IMC any day.
 
RMC weighs more than IMC and if weight is an issue IMC could fill the void. Also imc has a larger internal diameter than rmc.
 
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480sparky said:
But, it's in The Book (Art. 342)........
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So is MI (Art. 332).... and I would bet the majority of the members here have never used it or would know it if they saw it. :wink:


Roger
 
tkb said:
IMC isn't made with the best steel.
It is not the best to try to thread.

I would pick GRC over IMC any day.
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I agree, and you have to be very careful with the field cut thread depth on the 1/2 and 3/4 sizes of IMC. It is a fine line between getting the threads deep enough to thread into conduit bodies and keeping them shallow enough so that the pipe does not break off at the threads with a small amount of pressure.
 
don_resqcapt19 said:
I agree, and you have to be very careful with the field cut thread depth on the 1/2 and 3/4 sizes of IMC. It is a fine line between getting the threads deep enough to thread into conduit bodies and keeping them shallow enough so that the pipe does not break off at the threads with a small amount of pressure.
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I shouldn't be looked at like thin wall rigid pipe, but like thick wall EMT.:grin:
 
How does IMC compare to rigid and EMT as far as corrosion resistance? I work in a corrosive environment where EMT deteriorates quickly, but not everything has to be as heavy-duty as rigid.

-John
 
mike abbott said:
For what reasons would a customer or a contractor choose the added expense of GRC vs IMC in a factory?
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I am not aware of any location that grc is acceptable that imc is not also allowed.

I seem to recall a study that mentioned IMC has a superior annular (crush) strength to RMC (they claimed it was tougher because of the materials used ).

They sell a set of dies for IMC (IMC has a different OD from RMC)

IMC was surposed to replace RMC but it hasen't caught on (to my knowledge)
 
I just installed about 400' of 1" IMC. First time I had ever used it and it seemed very easy compared to RMC. Heck of a lot easier to bend at least. I guess my only concern is that it doesn't feel like it is a tight fit in the couplings even though the threads are bottomed out. I'm a little concerned about water-tightness. Should I be?
 
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