Working with rigid

J

jared123

Member
Location
Texas
Occupation
Electrician
I am JIW with mainly commercial experience. Have bent/threaded rigid mainly for underground changovers so precision wasnt paramount.
What technical advice do you have for working with rigid. Eg if i calculate the gain so i can predermine the length of rigid and thread it before bending do you assume it wont fully thread on and take that into account?
Thanks
 
I have experienced where sometimes it threads on maybe 3/4 of the way. Still tight but leaving some threads even from the factory. It has definitely occurred when we threaded it ourselves and i knew it was our inexpetience with threading.
 
jared123 said:
I am JIW with mainly commercial experience. Have bent/threaded rigid mainly for underground changovers so precision wasnt paramount.
What technical advice do you have for working with rigid. Eg if i calculate the gain so i can predermine the length of rigid and thread it before bending do you assume it wont fully thread on and take that into account?
Thanks
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Oil it, run it back and fro slowly and run it in more.
Oh, and get new dies.
 
hillbilly1 said:
Factory threaded fittings are not as tapered.
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They are required to have the same 3/4" per foot taper as field cut threads.
From UL 6, the product standard for RMC.
5.4.4 Taper of threads
5.4.4.1 The taper of threads shall be 1 in 16 (3/4 inch per foot), and the perfect thread (See L2 in Figure
5.1) shall be tapered for its entire length.[/quote[
Click to expand...
 
Here's what I do. First, I rarely take into account the gain and stretch. I make my bend, usually a short sweep or a small offset (gotta be able to spin it on), and then using the measurement for the length I need, I cut and thread the other end of the piece. If going into a fitting, I add 5/8". If going into a coupling, half the coupling minus up to 1/8". If the conduit doesn't want to thread into a fitting the full 5/8" and it is critical, I use a bigger pipe wrench.

Sometimes you gotta use a union because you can't spin it, and sometimes because you can't measure it. I try to avoid them.

One tip, in case you didn't know. when continuing a run with a "C" or a coupling, have it almost hand tight on one piece. Mate to the other piece and turn the "C" or coupling to engage a few thread, instead of trying to spin the entire piece.

And if you are using adjustable dies. like on a Rigid 300, find exactly where the threads are correct.
 
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rambojoe said:
Oil it, run it back and fro slowly and run it in more.
Oh, and get new dies.
Click to expand...
What I do out in the field, with anything threaded that doesn't feel right going together. Oil is your friend. My personal favorite "go to" oil when assembling stuff is just old school Dextron ATF, sometimes thinned with #2 fuel. ATF has a really high detergent content. Not sure if you've built auto transmissions , but if you do, your hands come really clean, even grease stained callouses that were there before you even touched the trans.

And yeah I know "gloves for PPE" but that's not what we did back then
 
TwoBlocked said:
Serious question here. Does Rigid sell different dies for pipe and for conduit? If so, what are the part numbers for hand threading.
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The dies are required to be the same (NPT) for plumbing and electrical. There is a straight thread machine tool die for but that is not NEC approved for field threads.
 
infinity said:
The dies are required to be the same (NPT) for plumbing and electrical. There is a straight thread machine tool die for but that is not NEC approved for field threads.
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I'm not asking anyone to prove something doesn't exist (kinda hard to do...) just giving others a chance to prove something does exist (much easier to do ;) )
 
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