Steel Pipe Wall Thickness & Schedule Chart
Find the outside diameter and nominal wall thickness behind common NPS, DN, and Schedule designations before planning a grooving or fabrication setup.
Translate the pipe callout into usable dimensions
A nominal size is a designation, not a direct measurement. Follow the row from the specified size to its actual outside diameter, then across to the required Schedule column.
- 01Locate NPS or DN
Start with the designation shown on the pipe specification.
- 02Confirm actual OD
Use the third column to verify the pipe outside diameter in millimeters.
- 03Read the Schedule
Move across the same row to obtain the listed nominal wall thickness.
Steel Pipe OD and Wall Thickness
Search by NPS, DN, or outside diameter. The finder first returns an exact size match; if none exists, it shows partial matches. A dash indicates that the supplied worksheet does not list a value.
| 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 | — | — |
| No pipe size matched that entry. Try a nominal size, DN, or outside diameter. | ||||||||||
What each value tells the fabricator
Nominal Pipe Size
An inch-based designation used to identify a pipe size. It should not be treated as the measured outside diameter.
Nominal Diameter
The corresponding metric designation used for identification and specification, not a measured diameter value.
Outside Diameter
The actual external diameter listed in millimeters. This is a key dimension for machine setup and groove geometry.
Schedule Series
A wall-thickness series. For one NPS, OD remains constant while the listed wall thickness changes by Schedule.
Technical note: The worksheet supplied for this page identifies ANSI B36.10 Schedule series and ANSI B36.19 stainless-steel series. Confirm material, tolerance, specification edition, and project requirements before fabrication. The chart is a reference, not a substitute for the governing standard.
Large-diameter application
Wall thickness is one part of machine selection
Pipe range, material, Schedule, forming method, and production workload all affect the equipment and roller configuration required for a reliable groove.
Have the pipe data, but not the machine setup?
Send GruvMaster the size range, material, maximum wall thickness, required groove standard, and expected daily workload. Our team can review the operating conditions and help narrow the suitable equipment configuration.
A complete application brief helps the engineering team respond with a more relevant recommendation.
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