Steel Pipe Wall Thickness Chart
Compare standard steel pipe sizes from NPS 1/2" to 48", including DN, actual outside diameter, and nominal wall thickness values in millimeters.
Pipe size and Schedule reference
Start with the actual pipe dimensions
Use this chart to compare nominal pipe size (NPS), nominal diameter (DN), actual pipe outside diameter, and the corresponding wall thickness for the Schedule designations included in the supplied worksheet.
For reliable fabrication and grooving, first confirm the outside diameter, then verify the pipe material, applicable Schedule series, manufacturing tolerance, and project standard.
Pipe Wall Thickness Table
Locate the pipe by NPS, DN, or outside diameter. A dash means no value is listed in the supplied reference table.
| NPS | DN | Pipe OD D (mm) |
Nominal Wall Thickness (mm) | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| SCH 5S | SCH 10S | SCH 10 | SCH 20 | SCH 30 | STD | SCH 40 | SCH 40S | |||
| 1/2" | 15 | 21.3 | 1.65 | 2.11 | 2.11 | — | 2.41 | 2.77 | 2.77 | 2.77 |
| 3/4" | 20 | 26.7 | 1.65 | 2.11 | 2.11 | — | 2.41 | 2.87 | 2.87 | 2.87 |
| 1" | 25 | 33.4 | 1.65 | 2.77 | 2.77 | — | 2.9 | 3.38 | 3.38 | 3.38 |
| 1-1/4" | 32 | 42.2 | 1.65 | 2.77 | 2.77 | — | 2.97 | 3.56 | 3.56 | 3.56 |
| 1-1/2" | 40 | 48.3 | 1.65 | 2.77 | 2.77 | — | 3.18 | 3.68 | 3.68 | 3.68 |
| 2" | 50 | 60.3 | 1.65 | 2.77 | 2.77 | — | 3.18 | 3.91 | 3.91 | 3.91 |
| 2-1/2" | 65 | 73 | 2.11 | 3.05 | 3.05 | — | 4.78 | 5.16 | 5.16 | 5.16 |
| 3" | 80 | 88.9 | 2.11 | 3.05 | 3.05 | — | 4.78 | 5.49 | 5.49 | 5.49 |
| 3-1/2" | 90 | 101.6 | 2.11 | 3.05 | 3.05 | — | 4.78 | 5.74 | 5.74 | 5.74 |
| 4" | 100 | 114.3 | 2.11 | 3.05 | 3.05 | — | 4.78 | 6.02 | 6.02 | 6.02 |
| 5" | 125 | 141.3 | 2.77 | 3.4 | 3.4 | — | — | 6.55 | 6.55 | 6.55 |
| 6" | 150 | 168.3 | 2.77 | 3.4 | 3.4 | — | — | 7.11 | 7.11 | 7.11 |
| 8" | 200 | 219.1 | 2.77 | 3.76 | 3.76 | 6.35 | 7.04 | 8.18 | 8.18 | 8.18 |
| 10" | 250 | 273 | 3.40 | 4.19 | 4.19 | 6.35 | 7.8 | 9.27 | 9.27 | 9.27 |
| 12" | 300 | 323.8 | 3.96 | 4.57 | 4.57 | 6.35 | 8.38 | 9.53 | 10.31 | 9.53 |
| 14" | 350 | 355.6 | 3.96 | 4.78 | 6.35 | 7.92 | 9.53 | 9.53 | 11.13 | — |
| 16" | 400 | 406.4 | 4.19 | 4.78 | 6.35 | 7.92 | 9.53 | 9.53 | 12.7 | — |
| 18" | 450 | 457.2 | 4.19 | 4.78 | 6.35 | 7.92 | 11.13 | 9.53 | 14.27 | — |
| 20" | 500 | 508 | 4.78 | 5.54 | 6.35 | 9.53 | 12.7 | 9.53 | 15.09 | — |
| 22" | 550 | 558.8 | 4.78 | 5.54 | 6.35 | 9.53 | 12.7 | 9.53 | — | — |
| 24" | 600 | 609.6 | 5.54 | 6.35 | 6.35 | 9.53 | 14.27 | 9.53 | 17.48 | — |
| 26" | 650 | 660.4 | — | — | 7.92 | 12.7 | — | 9.53 | — | — |
| 28" | 700 | 711.2 | — | — | 7.92 | 12.7 | 15.88 | 9.53 | — | — |
| 30" | 750 | 762 | 6.35 | 7.92 | 7.92 | 12.7 | 15.88 | 9.53 | — | — |
| 32" | 800 | 812.8 | — | — | 7.92 | 12.7 | 15.88 | 9.53 | 17.48 | — |
| 34" | 850 | 863.6 | — | — | 7.92 | 12.7 | 15.88 | 9.53 | 17.48 | — |
| 36" | 900 | 914.4 | — | — | 7.92 | 12.7 | 15.88 | 9.53 | 19.05 | — |
| 38" | 950 | 965.2 | — | — | — | — | — | 9.53 | — | — |
| 40" | 1000 | 1016 | — | — | — | — | — | 9.53 | — | — |
| 42" | 1050 | 1066.8 | — | — | — | — | — | 9.53 | — | — |
| 44" | 1100 | 1117.6 | — | — | — | — | — | 9.53 | — | — |
| 46" | 1150 | 1168.4 | — | — | — | — | — | 9.53 | — | — |
| 48" | 1200 | 1219.2 | — | — | — | — | — | 9.53 | — | — |
Three checks before fabrication
Confirm the pipe size
Match the NPS or DN designation, then verify the actual outside diameter in the third column.
Select the correct series
Schedule numbers identify wall-thickness series. An “S” suffix marks a stainless-steel Schedule series in the source table.
Verify the project standard
Confirm material, tolerance, specification, and the current governing standard before cutting, grooving, or installation.
Reference note: The supplied worksheet identifies ANSI B36.10 Schedule series and ANSI B36.19 stainless-steel series. Only the columns contained in that worksheet are reproduced here. Values are a technical reference and should be checked against the governing project standard.
Need help matching your pipe range to the right machine?
Send WELPING your actual pipe dimensions, material, process, and expected output. Our team can use those details to recommend a suitable roll groover, groove cutter, or pipe cutting solution for your application.
Share the real operating data for a more precise, project-specific recommendation.
Send Your Pipe Details Our team will review the application details you provide.