Pipe fences are pretty common locally and are usually built out of what's typically just called "oil field pipe" which is usually 2-3/8 inch pipe that's either used or new (new pipe is a heck of a lot easier to work with). The posts are usually about 8 feet apart, the top rail is around 4-5 foot from the ground, and cable, sucker rod, or tubing is used for the rails. Like everything, some fences are almost works of art, and some fences look like whoever built them was mad at the world at the time so they just slapped a bunch of pipe together and started welding.
Back when I was thinking about building my working pens and the fence along the road in front of the barn, I had all sorts of ideas about how I was going to cut those saddle notches on the top of the posts for the top rail to set in, but could never really figure out the best way to go about it. Then, when I was looking at a little haybine that I was thinking about buying, I noticed that the seller had some really nice looking pipe fences around his house, and uncharacteristically for me, I simply asked him, "How the heck did you cut those saddle notches for your fence?" It turned out that he was a welder and also owned a trailer building business, and he told me that most welding supply places sold these spring-loaded templates that made it easy to layout the saddle cut so it could be cut with a torch. (Man alive, it takes me forever to get to the point of my story sometimes doesn't it?).
Everything I'd seen before had involved a bunch of nonsense like using a chop saw to cut a couple of angle cuts followed by a straight cut on the post, or holding the top rail on top of the post and scribing the saddle notch. I had a pretty good idea that a tool like this existed, but I might have never found it on my own without asking someone about how they built their pipe fence.
After that long-winded introduction, here's what the tool looks like, I tried to look online for one so I could add a link but didn't come up with anything similar (which might be why I never found one until I started asking people about pipe fences), but I bought mine at the same place that I bought my steel pipe. I'm pretty sure that most places selling the pipe would also sell a similar tool or could point to the right place to find one for anyone that's interested in trying their hand at building a pipe fence.
|That red thing is the tool we're talking about (ignore the mess)|
|After cutting the saddle notch|
|Ready to weld together|
UPDATE: For anyone that happens to stumble across this post and is interested in buying a pipe cutting guide to build their own pipe fence, I finally found the tool I used online at: http://www.nationwide-products.com/pipeproguides/index.html