Schedule 80 pipe dimensions
Extra-strong (Schedule 80) carbon steel pipe dimensions per ASME B36.10, from 1/8 to 12 inch nominal size. Schedule 80 shares the same outside diameter as Schedule 40 for each size but has a thicker wall, giving a higher pressure rating and a smaller bore.
Schedule 80 steel pipe
| NPS | OD (in) | Wall (in) | ID (in) | Weight (lb/ft) |
|---|---|---|---|---|
| 1/8 | 0.405 | 0.095 | 0.215 | 0.31 |
| 1/4 | 0.540 | 0.119 | 0.302 | 0.54 |
| 3/8 | 0.675 | 0.126 | 0.423 | 0.74 |
| 1/2 | 0.840 | 0.147 | 0.546 | 1.09 |
| 3/4 | 1.050 | 0.154 | 0.742 | 1.47 |
| 1 | 1.315 | 0.179 | 0.957 | 2.17 |
| 1-1/4 | 1.660 | 0.191 | 1.278 | 3.00 |
| 1-1/2 | 1.900 | 0.200 | 1.500 | 3.63 |
| 2 | 2.375 | 0.218 | 1.939 | 5.02 |
| 2-1/2 | 2.875 | 0.276 | 2.323 | 7.66 |
| 3 | 3.500 | 0.300 | 2.900 | 10.25 |
| 4 | 4.500 | 0.337 | 3.826 | 14.98 |
| 5 | 5.563 | 0.375 | 4.813 | 20.78 |
| 6 | 6.625 | 0.432 | 5.761 | 28.57 |
| 8 | 8.625 | 0.500 | 7.625 | 43.39 |
| 10 | 10.750 | 0.500 | 9.750 | 54.74 |
| 12 | 12.750 | 0.687 | 11.376 | 88.51 |
The outside diameter matches Schedule 40 for each NPS, so Schedule 80 fittings and threads interchange dimensionally, but the thicker wall reduces the inside diameter and flow area. Weights are nominal for plain carbon steel.
Comparing against standard-weight pipe?
See the Schedule 40 Pipe Dimensions chart for the standard-weight equivalent.
When to use Schedule 80
Schedule 80 is chosen for higher pressure, mechanical abuse, or threaded connections, where the extra wall gives a margin of strength. The thicker wall also leaves more material for pipe threads, which cut into the wall. The trade-offs are more weight, higher cost, and a smaller flow area than Schedule 40.
Pressure and bore trade-off
Going from Schedule 40 to 80 raises the pressure rating but shrinks the bore. A 2 inch Schedule 80 pipe has a 1.939 inch inside diameter versus 2.067 for Schedule 40, cutting flow area by about 12 percent. Size the bore for flow and pick the schedule for pressure.
FAQ
What is the inside diameter of 2 inch Schedule 80 pipe?
About 1.939 inches, with the same 2.375 inch outside diameter as Schedule 40 but a thicker 0.218 inch wall.
Is Schedule 80 stronger than Schedule 40?
Yes. The thicker wall gives Schedule 80 a higher pressure rating and more durability, at the cost of more weight and less flow area.
Can Schedule 40 and 80 pipe connect together?
Dimensionally yes, since they share the same outside diameter and threads. But the bore steps at the joint and pressure ratings differ, so match the system requirements.