Understand and measure your fence pipe accurately to prevent misorders and misfitting hardware.
Most returns for chain link fence hardware are due to a simple and preventable mistake: the wrong size was ordered. In most cases, this comes down to incorrect measurements or confusion about how pipe sizing works. This guide breaks down the key measurements in chain link fence pipe and how to accurately measure fence pipe diameter, so you can order the right hardware the first time.
Fence pipe vs. plumbing pipe: What's the difference?
If you're used to working with plumbing pipe, fence pipe can be confusing. Although they may look similar, they are measured differently—and that difference matters.
Chain link fence pipe, sometimes called tubing, is measured by its outside diameter (OD). This includes the full width of the pipe, walls and all. In contrast, plumbing pipe is measured by the inside diameter (ID), meaning only the opening of the pipe is measured.
This distinction is one of the biggest sources of ordering mistakes.
Key pipe measurements
When buying chain link fence hardware, the most important measurement is the outside diameter, but it's helpful to understand some of the other key terms that you may see in pipe sizing.
Nominal pipe size (NPS)
Nominal pipe size (NPS) is a nondimensional labeling standard, referring to the general pipe size. It is not an exact measurement of either the inner or outer diameter of the pipe, so it can be misleading when ordering fence parts.
| Common Pipe Sizes (NPS vs. OD) | ||
|---|---|---|
| NPS | OD | |
| Inches | Fraction | |
| 3/8 | 0.6750 | 11/16 |
| 1/2 | 0.8400 | 13/16 |
| 3/4 | 1.050 | 1-1/16 |
| 1 | 1.315 | 1-5/16 |
| 1-1/4 | 1.660 | 1-11/16 |
| 1-1/2 | 1.900 | 1-7/8 |
| 2 | 2.375 | 2-3/8 |
| 2-1/2 | 2.875 | 2-7/8 |
| 3 | 3.500 | 3-1/2 |
| 3-1/2 | 4.000 | 4 |
Inner diameter (ID)
The inner diameter is the width of the pipe opening, excluding the walls. This measurement is mainly relevant for plumbing pipe, not fencing.
How to measure fence pipe
What you'll need: A tape measure, ruler, or calipers.
Process: Use your measuring tool to find the distance across the pipe, including the walls. If you cannot access the open end of the pipe, calipers are the most reliable way to measure diameter while working around the pipe.
If you have any questions about pipe sizing or need help finding the right hardware, don't hesitate to contact our friendly experts at (406)752-5253 or send us an email at tom@jakesales.com.
FAQ
What size is standard chain link fence pipe?
Most residential fence posts are 1-3/8", 1-5/8", or 2-3/8" outside diameter.
Is chain link fence measured by ID or OD?
Chain link fence pipe is measured by the outside diameter (OD), not inside diameter(ID).
Why doesn't nominal pipe size match actual size?
Nominal pipe size (NPS) is a labeling system, not an exact measurement, so it doesn't reflect the true outer diameter.
How do I measure fence pipe without calipers?
If you cannot measure across the open end of the pipe, wrap a tape measure around the pipe to find the circumference, then divide by 3.1416 (𝛑) to get the diameter.
Can I use plumbing pipe for a chain link fence?
Yes, you can use plumbing pipe for a chain link fence if the outer diameter matches. Always double check your measurements before beginning a project.
What happens if I order the wrong pipe size?
Fence hardware won't fit properly, and you may need to return and reorder your fittings.
Orders returned within 30 days are charged a 15% restocking fee, so it's important to order the right size the first time around. See our return and refund policies for more information.