How to Choose the Right Size Pipe for Your Fence

Congratulations!  You've chosen to build your fence from pipe!  If you're at this point, you already know that your fence will be the longest lasting, strongest, and easiest to maintain fence, as well as attractive, and the most adaptable to you and/or your livestock's needs.  But now that you've made the decision to build your pipe fence, how do you decide what the best pipe size is?

There are many considerations that go into designing a fence and choosing the right size of pipe will make sure that you have the perfect fence.  Horse fencing, for example, needs to be highly visible, strong enough for the horse to lean on it, and yet flexible enough to prevent injury.  A large diameter, lighter weight, high tensile pipe is perfect for horses.  In fact, increasing the diameter (without increasing the thickness) multiplies the load that a single piece of pipe can bear exponentially.  A single size, or weight, of pipe absolutely does not fit all.  Buying the correct size will make your fence safer, stronger, and more cost effective.

How much weight must be applied to a single piece of pipe or tubing before it bends?
 

(Hint...It's not what you think!)

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There are a lot of choices of pipe for your fence.  Buying fence pipe can be extremely confusing since everyone seems to have a different opinion of the best size to use.  The truth is that each supplier that you call is going to recommend whatever they have an excess of or need to sell for some reason.  In some areas, oilfield sizes are the most popular since they are the most readily available.  But, is a standard oilfield pipe really the best choice?  Not necessarily.  In fact, one would think that a light wall tube would bend much easier than a solid bar, but nothing could be farther from the truth! 

We recognize that there are a lot of factors that go into building a quality pipe fence and the size of the pipe is just one of them. But when comparing sizes of pipe and tubing, the size that can handle the heaviest load is not necessarily the one with the thickest wall. 

Compare the 2-3/8" 9 gauge (schedule 40) to the 2-7/8" 13 gauge.  The lighter wall 2-7/8" is over 30% cheaper and 14% stronger.  For 5,000 feet, that's a savings of $1,500!!

We put

2-7/8" 13 gauge to the test:

And when the weight was removed...

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While the calculations are beyond the scope here, the internet is full of engineering and design sites to verify any of this.  Hopefully the chart below will help find the right size and the right price for your next project!  All weights assume a 10' span.

Notes:

  • Chart is based on a 10' span.  A 5' span will double the amount of weight supported.

  • 1-1/4" solid bar will support 400 pounds.