Conduit tube question

Is there a tool to shrink the end of a piece of conduit so it will slip into another piece of the same size? I have seen tubing for toys and what have you that was crimped like that but I don't know if you can do this to conduit. I can probably make something but if a tool is readily available I would just as soon buy one. Rusty.

 

I've been an electrician for over thirty years and I've never seen anything like you're looking for. You might be able to get it done at a muffler shop depending on what size of conduit you're talking about. Conduit, both rigid steel and aluminum, as well as EMT ( electrical metalic tubing also known as "thinwall") is put together with couplings.

 

Don't know anything about the tool, but the process is called either swedging or swaging (I think).

 

Rigid has them, we use one that works with 1/4" to 3/4" id pipe. They call it just Tubing Expander Model "S". Hope this helps.

 

I was going to suggest something similar, but he said he wants to "shrink" conduit. I am not aware of such a tool-expander, yes, shrinker, no.

 

Yup, I screwed up. I realized he said shrink after I posted. Sorry about that.

 

yea, i got serious doubts on shrinkin one end to fit... you are lookin at makin the stuff longer and keeping the diameter consistant am i right?

only alternative would be to take a small section of tube, slice it lengthways and roll it smaller (think sleeve) then slip it inside of a butt joint and tac it tight with a couple of rosette welds and weld the seam up...

let us know how you manage

 

If you are merely wanting to put one end of conduit into another you can use the swaging tool, as explained above, to make one end larger, and slip a "stock" one into it.
If you insist, for some reason, that one end must be made smaller, to fit into a "stocker", you can make a tool that should work. We bodymen shrink metal all the time! Get a big chunk of aluminum, and drill out a hole the size you want the end fo the conduit to be. Then make a 'bellmouth' leading into the hole. Kinda like a funnel, a smooth transition into the existing hole. I would use a large countersink, and finish with a die grinder and carbide bit, but you can use a die grinder, or even a round file for the job. Lube up the conduit, put it into the bellmouth, and then tap the aluminum over the conduit slowly. it should shrink the tubing into the size you want as it funnels down into the hole. You'll have to secure the rest of the conduit so it doesn't move away from the tool as you hit it, without damaging it, though.

 

Thanks to everone who posted. I didn't know about the tubing stretcher. That will work ok for a lot of what I want to do. To shrink it I thought about using piece of steel rod a little smaller that the tubing with a v-shaped groove cut in it. This should slip into the conduit and then use a dull chisel to hammer the side of the tube into the groove and shrink the tube. I'll post a pix if it works. Rusty.

 

For a "home model" tool you probably want something that looks like a tube cutter, but with a third roller where the cutter usually is.
No, I don't know if anyone makes one , yet...