"Schedule 40" refers to the wall thickness of the pipe. Schedule numbers are used to indicate the thickness of the walls, which in turn determines the pressure capacity of the pipe. The higher the schedule number, the thicker the wall and the greater the pressure capacity. Schedule 40 is considered a medium thickness pipe and is the most commonly used schedule for pipes in general applications.
| ASTM A53 and ASTM A106 Schedule 40 Steel Pipe Dimensions Chart | |||||
| Nominal size | DN | Outside diameter | Outside diameter | schedule 40 thickness | |
| Wall thickness | Wall thickness | ||||
| [inch] | [inch] | [mm] | [inch] | [mm] | |
| 1/2 | 15 | 0.84 | 21.3 | 0.109 | 2.77 |
| 3/4 | 20 | 1.05 | 26.7 | 0.113 | 2.87 |
| 1 | 25 | 1.315 | 33.4 | 0.133 | 3.38 |
| 11/4 | 32 | 1.66 | 42.2 | 0.14 | 3.56 |
| 11/2 | 40 | 1.9 | 48.3 | 0.145 | 3.68 |
| 2 | 50 | 2.375 | 60.3 | 0.154 | 3.91 |
| 21/2 | 65 | 2.875 | 73 | 0.203 | 5.16 |
| 3 | 80 | 3.5 | 88.9 | 0.216 | 5.49 |
| 31/2 | 90 | 4 | 101.6 | 0.226 | 5.74 |
| 4 | 100 | 4.5 | 114.3 | 0.237 | 6.02 |
| 5 | 125 | 5.563 | 141.3 | 0.258 | 6.55 |
| 6 | 150 | 6.625 | 168.3 | 0.28 | 7.11 |
| 8 | 200 | 8.625 | 219.1 | 0.322 | 8.18 |
| 10 | 250 | 10.75 | 273 | 0.365 | 9.27 |
ASTM A53 Schedule 40 Steel Pipe VS ASTM A106 Schedule 40 Steel Pipe
Grades: A and B
Grades: A, B, and C
Welded and seamless steel pipe.
Only seamless steel pipe
Conveying water, gas, and other fluids.
Structural applications.
Structural applications.
Boiler systems, pipelines in the oil and gas industry.
High-pressure and high-temperature service.
High-pressure and high-temperature service.
