In this post, I will demonstrate the important things you need to know about the Schedule 40 pipe (metal or steel pipe), the schedule 40 pipe dimensions chart, and how to read it.
Measuring a metal tube is pretty simple, generally all you need is a tape measure, just pull it out, and … psiizst. Done.
When it comes to measuring a metal pipe or steel pipe, things get a little trickier as we have to use the Nominal Pipe Size and Pipe Schedule numbers, and here the Pipe schedule comes in.
Schedule 40 Pipe Dimensions Chart
| Nominal Pipe Size | Outside Diameter | Schedule 40 Wall Thickness | Schedule 80 Wall Thickness |
|---|---|---|---|
| 1/8 | 0.405 | 0.068 | 0.095 |
| 1/4 | 0.54 | 0.088 | 0.119 |
| 3/8 | 0.675 | 0.091 | 0.126 |
| 1/2 | 0.84 | 0.109 | 0.147 |
| 3/4 | 1.05 | 0.113 | 0.154 |
| 1 | 1.315 | 0.133 | 0.179 |
| 1-1/4 | 1.66 | 0.14 | 0.191 |
| 1-1/2 | 1.9 | 0.145 | 0.2 |
| 2 | 2.375 | 0.154 | 0.218 |
| 2-1/2 | 2.875 | 0.203 | 0.275 |
| 3 | 3.5 | 0.216 | 0.3 |
| 3-1/2 | 4 | 0.226 | 0.318 |
| 4 | 4.5 | 0.237 | 0.337 |
| 5 | 5.563 | 0.258 | 0.375 |
| 6 | 6.625 | 0.28 | 0.432 |
| 8 | 8.625 | 0.322 | 0.5 |
| 10 | 10.75 | 0.365 | 0.594 |
| 12 | 12.75 | 0.406 | 0.688 |
| 14 | 14.00 | 0.375 | 0.750 |
| 16 | 16.00 | 0.375 | 0.843 |
| 18 | 18.00 | 0.375 | 0.937 |
| 20 | 20.00 | 0.375 | 1.031 |
| 22 | 22.00 | 0.375 | 1.125 |
| 24 | 24.00 | 0.375 | 1.218 |
Steel pipe Schedule 40 is one of the two most common pipe schedules (40 and 80). A pipe schedule is a non-dimensional number that relates to the thickness of the pipe wall and affects the inside diameter of the pipe. We use the pipe schedule to classify pipes for low or high pressure and temperature applications.
Nominal Pipe Size (NPS) is an American standard number used for iron pipe sizing, this number represents the approximate inside diameter of pipes, it is not exactly the dimension of the pipe, not the inside dimension (ID) nor the outside dimension (OD).
There are different pipe schedule numbers for the same nominal pipe size. The bigger the pipe schedule number, the thicker the pipe wall is, and the smaller pipe inside diameter.
That being said, a 1″ NPS schedule 40 pipe has a thinner wall and a bigger inside diameter than a 1″ NPS schedule 80 pipe, and it is used for lower pressure and temperature applications.
Pipe schedule 40 is also called Standard wall (STD) while schedule 80 is known as Extra Strong wall (XS)