RGS THreading

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Alwayslearningelec

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If yu gut a piece of RGS for a bend then you must thread where you cut, correct? Should the factory elbow always come with a coupling on each end? THanks.
 
horsegoer said:
If yu gut a piece of RGS for a bend then you must thread where you cut, correct?
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Typically, yes... but not absolutely. You could just ream the cut end and use threadless fittings.

Should the factory elbow always come with a coupling on each end?
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Seldom used on the jobs I work... but as I recall from the few times they were used, they had no couplings on them at all.
 
horsegoer said:
If you cut a piece of RGS for a bend then you must thread where you cut, correct?
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Yes but often not in that order.

Many times it is cut, thread and then bend. If you bend first it can make threading difficult to imposable.




Should the factory elbow always come with a coupling on each end? THanks.
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Should they? Maybe

Will they? No, there will just be male threads on each end of the 90.
 
iwire said:
Yes but often not in that order.

Many times it is cut, thread and then bend. If you bend first it can make threading difficult to imposable.






Should they? Maybe

Will they? No, there will just be male threads on each end of the 90.
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And that is to screw the coupling on???
 
1: It depends on how many cuts are there and the size of it. For 2-3 cuts of 3/4 GRC is not worth to bring out the threader and the vice for $ 3.00-4.00 compression couplings. If I have a few hundred, you bet I'll set up the threader. Or a few 2". Last time I bought a compression coupling for a 2" GRC was around $ 40.00. That is if you have to use compression. Things could be different for set screw which are relatively way cheaper.
2: The GRC Conduit comes with a threaded coupling so I don't see a reason to have a threaded coupling in a factory made elbow.

horsegoer said:
If yu gut a piece of RGS for a bend then you must thread where you cut, correct? Should the factory elbow always come with a coupling on each end? THanks.
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Strife said:
1: It depends on how many cuts are there and the size of it. For 2-3 cuts of 3/4 GRC is not worth to bring out the threader and the vice for $ 3.00-4.00 compression couplings. If I have a few hundred, you bet I'll set up the threader. Or a few 2". Last time I bought a compression coupling for a 2" GRC was around $ 40.00. That is if you have to use compression. Things could be different for set screw which are relatively way cheaper.
2: The GRC Conduit comes with a threaded coupling so I don't see a reason to have a threaded coupling in a factory made elbow.
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But if you bend/elbow takes place not at the end of your 10/20' tick then you would have to cut and then you would need to thread, right? And if you use a factory elbow(those are your two options right?? factory elbow or bend yourself???) it does not come with a coupling most times from what someone else said. THanks.
 
horsegoer said:
But if you bend/elbow takes place not at the end of your 10/20' tick then you would have to cut and then you would need to thread, right? And if you use a factory elbow(those are your two options right?? factory elbow or bend yourself???) it does not come with a coupling most times from what someone else said. THanks.
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As Bob said, SOP is: cut, thread, bend.
 
horsegoer said:
But if you bend/elbow takes place not at the end of your 10/20' tick then you would have to cut and then you would need to thread, right? And if you use a factory elbow(those are your two options right?? factory elbow or bend yourself???) it does not come with a coupling most times from what someone else said. THanks.
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If the point of your questions is that factory 90's should come with at least one coupling, I agree it would be beneficial for purchasing and installation. Now you just have to convince manufacturers...
 
kwired said:
Sometimes you bend first otherwise there is nothing left to hold onto to bend it after it is cut. Depends on what bender you are using also.
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Usually it is bend, cut, thread with most electricians that I've worked with. If you can't thread it after bending, your stub is too short or you don't have the proper equipment for doing the job.

I'm not saying you can't cut and thread before bending...
 
Smart $ said:
Usually it is bend, cut, thread with most electricians that I've worked with. If you can't thread it after bending, your stub is too short or you don't have the proper equipment for doing the job.

I'm not saying you can't cut and thread before bending...
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A person skilled in the art of running threaded pipe will cut, thread and then bend. It takes more math and more experience, but that is where the skilled part comes into play.

A skilled threaded pipe installer will be able to make several bends in one pipe that would prevent the pipe from being held into a threader and since the threads are already there, no problem.

Using a porta pony is a way around this, but using one on 2 inch and larger pipe is probably not going to happen.

A skilled threaded pipe installer will be able to figure take up and shrink so the pipe can be threaded before it is bent and it will be the correct length when done.

I can look at a run and most of the time tell if it was run by a skilled installer, or one that had to use cheaters because they could only thread pipe that was straight enough to fit into a threader.

Try threading a piece of 3 inch rigid with a 90 bent in the middle of it.
 
iwire said:
It gets ugly spinning conduits with 90s or other large bends already in them. :)
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Yes it does. If one is resolved to using a threading machine, cutting and threading first would be advisable in those cases, especially for larger sizes of conduit. But a power pony set up will suffice. However, some think that is too much bother when you have a threading machine setting there. That's more a personal preference rather than a matter of necessity. You can't cut, thread, then bend a stub any shorter than you can bend, cut, then thread one with a power pony, at least on smaller size conduits. With large conduit, a pony driven thread head may not allow getting as short a stub as a machine threading first. Other than these short stub situations, it is seldom necessary to cut and thread before bending when all the proper tools are available.
 
iwire said:
It gets ugly spinning conduits with 90s or other large bends already in them. :)
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Usually you can swing up one leg, spin the big 90 on and then drop it back to the wall. If you can't, you can't and would have to use a stub 90 and a nipple. I have seen racks of rigid bent in the middle with all the couplings lined up in a concentric bend. I think there were 7 pipes on the racks. It was in a power plant and one of the most beautiful runs of rigid I have ever seen. The guy that did it was a real artist and I know that all the pipe was threaded before it made it to the bender.
 
K8MHZ said:
A person skilled in the art of running threaded pipe will cut, thread and then bend. It takes more math and more experience, but that is where the skilled part comes into play.

A skilled threaded pipe installer will be able to make several bends in one pipe that would prevent the pipe from being held into a threader and since the threads are already there, no problem.

Using a porta pony is a way around this, but using one on 2 inch and larger pipe is probably not going to happen.

A skilled threaded pipe installer will be able to figure take up and shrink so the pipe can be threaded before it is bent and it will be the correct length when done.

I can look at a run and most of the time tell if it was run by a skilled installer, or one that had to use cheaters because they could only thread pipe that was straight enough to fit into a threader.

Try threading a piece of 3 inch rigid with a 90 bent in the middle of it.
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Typing my reply to Bob when you posted, but I think I covered about everything you mentioned in that reply.
 
K8MHZ said:
Usually you can swing up one leg, spin the big 90 on and then drop it back to the wall. If you can't, you can't and would have to use a stub 90 and a nipple. I have seen racks of rigid bent in the middle with all the couplings lined up in a concentric bend. I think there were 7 pipes on the racks. It was in a power plant and one of the most beautiful runs of rigid I have ever seen. The guy that did it was a real artist and I know that all the pipe was threaded before it made it to the bender.
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He was referring to sticking a long stub 90 into a threading machine... but installing them afterwards can definitely be a challenge ;)

BTW, I've had to unstrut 30' of 4" rigid just to spin on a 90. Of course I had a little help in doing it.
 
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Other than these short stub situations, it is seldom necessary to cut and thread before bending when all the proper tools are available.
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Key words.

As an IBEW Journeyman, I am expected to be able to run rigid without using porta ponies as I was trained to be able to do so without special tools. As such, trying to get a porta pony on my site because I didn't know how to cut and thread before I made my bends wouldn't fare well with my supervisor, I will guarantee you that.

On most of the big jobs there will be one nasty threader and if you are lucky a 555 that runs on after you release the button. Hopefully, the reamer on the threader won't be worn out so bad it is useless.

Seriously, I know when I show up on a job running rigid I will be expected to know how to calculate take up and shrink and only put straight pieces or pieces of pipe with a stub 90 on it into the threader. A substantial part of my apprenticeship was centered around running threaded pipe. In class, we were tested on how well we knew the ins and outs of bending threaded pipe.
 
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