EMT Conduit is a great building material for DIY projects and we offer various connectors and solutions for connecting pieces of 3/4" EMT Conduit together. Members of the community often ask us how they can connect two pieces of conduit end-to-end so today we are going to look at a few different methods for doing just that.
Usually we don't recommend that you connect EMT Conduit this way because long unsupported spans pipe could cause issues in your build. That reason specifically is why we've never produced a connector for this kind of solution. Be sure to test any of these options for yourself and make sure that it is the right solution for your specific project.
With that said let’s look at some different ways, you can connect two pieces of conduit end to end.
If you are familiar with our system of connectors then you have probably seen the 180 Degree Connector. It allows you to connect two pipes at 180 degrees with a vertical support pipe in the middle. That center pipe is necessary for the connector to work as it should, but what you can do is grab one of these ½” threaded steel couplings from the plumbing aisle of your local hardware store and use it in the middle like this. If you use a stub piece of conduit, it’ll squish too much, and won’t offer enough support for the connector.
We also offer threaded tube inserts on the site and they open up a few end to end connection possibilities. We offer two sizes, ¼-20 and ⅜-16. For end-to-end connections, you’ll definitely want to use the larger ⅜-16 inserts. These can be hammered or pressed into the ends of conduit with a vice, and they add a threaded mounting point in the conduit end. You can join two pieces of conduit together if you add inserts to the conduit and then thread them together with a threaded rod.
This method will provide decent pull-out strength, but it will flex pretty easily in the middle because the threaded rod isn’t touching the inner wall of the conduit. Jay from Martin Product Design in Wisconsin recommended a method for reinforcing this connection and it’s really cool.
You'll start by getting one of these 3/8-16 threaded rods that is 3" in length, and then add a 3/8-16 nut about a quarter of the way up. Then you will stack five of these M10 fender washers on top of the nut. On top of those you will add two M12 fender washers. To finish off the reinforcement solution you will add five more of the M10 washers, and another 3/8-16" nut. You may have to adjust the washers a bit so they sit flush with each other, but in the end you should get something that looks like the picture above.
Once you add your two no lip threaded inserts into your pipe and thread everything together you will have a strong end-to-end connection. It’s important to note that the conduit needs to be completely de-burred so the washers can slide into the conduit ends. A portable band saw will work best here, but if you only have the pipe and tube cutter, make sure to de-burr as much as possible.
Next up is a solution that utilizes off-the-shelf components. You can buy two different types of EMT Conduit couplings at your local hardware stores.
One has set screws and all you have to do is slide the conduit pipes in on each side and tighten the set screws. If you want to make this even more secure, you can take out the set screws completely and use metal self-tapping screws to secure them.
Another off-the-shelf option is the double-sided compression fittings that work similarly to the set screw except there are rings on the inside that squeeze the conduit while you tighten them.These two off-the-shelf parts will offer decent pull-out strength, but you can also combine them with a method from earlier for a really strong end-to-end connection. 3/
These couplings are hollow all the way through which means we can add a tube insert with a threaded rod through them easily. This will give you a really strong joint between the two pipes.
While I was at the hardware store I found this ribbed ¾” insert coupling that works well and is pretty strong. The only reason it’s not my favorite solution is because it’s gonna be hard to hammer in when you’re working with longer pieces of pipe.
The last solution that I want to recommend utilizes this metal stake that I bought at home depot. Normally these are great for securing builds in the ground but you can slide two pieces of conduit over them. You still need a way to connect the two pipes together and you can do that easily with one of the set screw couplings.
I hope you found this blog helpful. Remember to build safely and if you need any help feel free to reach out to us. Thanks for reading and happy building!