Schedule #40 Pipe Specifications
| Pipe Size | Pipe Size | Pipe Size | Pipe Size | |
| I.D. | I.D. | O.D. | O.D. | Threads |
| Fractional | Decimal | Fractional | Decimal | Per Inch |
| 1/8 | .125 | 25/64 | .405 | 27 |
| 1/4 | .250 | 17/32 | .540 | 18 |
| 3/8 | .375 | 43/64 | .675 | 18 |
| 1/2 | .500 | 53/64 | .840 | 14 |
| 3/4 | .750 | 1 3/64 | 1.050 | 14 |
| 1 | 1.000 | 1 5/16 | 1.315 | 11 1/2 |
| 1 1/4 | 1.250 | 1 21/32 | 1.660 | 11 1/2 |
| 1 1/2 | 1.500 | 1 57/64 | 1.900 | 11 1/2 |
| 2 | 2.000 | 2 3/8 | 2.375 | 11 1/2 |
| 2 1/2 | 2.500 | 2 7/8 | 2.875 | 8 |
| 3 | 3.000 | 3 1/2 | 3.500 | 8 |
| 3 1/2 | 3.500 | 4 | 4.000 | 8 |
| 4 | 4.000 | 4 1/2 | 4.500 | 8 |
| 5 | 5.000 | 5 9/16 | 5.563 | 8 |
| 6 | 6.000 | 6 5/8 | 6.625 | 8 |
| 8 | 8.000 | 8 5/8 | 8.625 | 8 |
| 10 | 10.000 | 10 3/4 | 10.750 | 8 |
| 12 | 12.000 | 12 3/4 | 12.750 | 8 |