NPS & DN
Nominal Pipe Size (inches) and Diametre Nominal (mm) are labels, not measurements. NPS 2″ equals DN 50.
Dimensional Charts
Pipe Schedule & Dimensional Charts
Outside diameter and wall thickness for every common pipe size and schedule, plus tube gauges — with a finder that works out inside diameter and weight per metre for you.
Basics
Four Terms You Need to Read a Pipe Size
Learn these four and every pipe chart becomes easy to read.
Outside Diameter
The OD is fixed for each NPS — for example 60.3 mm for NPS 2″ — whatever the schedule. Only the wall changes.
Schedule
A number that sets wall thickness for each NPS. A higher schedule means a thicker wall and a smaller bore.
The “S” Suffix
5S, 10S, 40S and 80S are the stainless schedules of ASME B36.19M. Carbon and alloy pipe use B36.10M with STD, XS and numbered schedules.
Pipe Finder
Look Up a Pipe in Three Clicks
Pick a size, a schedule and a material to get the wall thickness, bore and weight per metre.
Schedule Charts
Wall Thickness by Size and Schedule
All wall thicknesses in millimetres. A dash means the schedule is not defined for that size.
Hover any cell to trace its row and column
| NPS | DN | OD (mm) | Sch 5S | Sch 10S | Sch 40S | Sch 80S |
|---|---|---|---|---|---|---|
| ⅛″ | 6 | 10.3 | — | 1.24 | 1.73 | 2.41 |
| ¼″ | 8 | 13.7 | — | 1.65 | 2.24 | 3.02 |
| ⅜″ | 10 | 17.1 | — | 1.65 | 2.31 | 3.20 |
| ½″ | 15 | 21.3 | 1.65 | 2.11 | 2.77 | 3.73 |
| ¾″ | 20 | 26.7 | 1.65 | 2.11 | 2.87 | 3.91 |
| 1″ | 25 | 33.4 | 1.65 | 2.77 | 3.38 | 4.55 |
| 1¼″ | 32 | 42.2 | 1.65 | 2.77 | 3.56 | 4.85 |
| 1½″ | 40 | 48.3 | 1.65 | 2.77 | 3.68 | 5.08 |
| 2″ | 50 | 60.3 | 1.65 | 2.77 | 3.91 | 5.54 |
| 2½″ | 65 | 73.0 | 2.11 | 3.05 | 5.16 | 7.01 |
| 3″ | 80 | 88.9 | 2.11 | 3.05 | 5.49 | 7.62 |
| 3½″ | 90 | 101.6 | 2.11 | 3.05 | 5.74 | 8.08 |
| 4″ | 100 | 114.3 | 2.11 | 3.05 | 6.02 | 8.56 |
| 5″ | 125 | 141.3 | 2.77 | 3.40 | 6.55 | 9.53 |
| 6″ | 150 | 168.3 | 2.77 | 3.40 | 7.11 | 10.97 |
| 8″ | 200 | 219.1 | 2.77 | 3.76 | 8.18 | 12.70 |
| 10″ | 250 | 273.1 | 3.40 | 4.19 | 9.27 | 12.70 |
| 12″ | 300 | 323.9 | 3.96 | 4.57 | 9.53 | 12.70 |
| 14″ | 350 | 355.6 | 3.96 | 4.78 | — | — |
| 16″ | 400 | 406.4 | 4.19 | 4.78 | — | — |
| 18″ | 450 | 457.0 | 4.19 | 4.78 | — | — |
| 20″ | 500 | 508.0 | 4.78 | 5.54 | — | — |
| 24″ | 600 | 610.0 | 5.54 | 6.35 | — | — |
Stainless-steel pipe schedules ending in “S”. 5S and 10S are thin-wall schedules used only for stainless. 40S and 80S are available up to NPS 12.
| NPS | DN | OD (mm) | STD | Sch 40 | XS | Sch 80 | Sch 160 | XXS |
|---|---|---|---|---|---|---|---|---|
| ⅛″ | 6 | 10.3 | 1.73 | 1.73 | 2.41 | 2.41 | — | — |
| ¼″ | 8 | 13.7 | 2.24 | 2.24 | 3.02 | 3.02 | — | — |
| ⅜″ | 10 | 17.1 | 2.31 | 2.31 | 3.20 | 3.20 | — | — |
| ½″ | 15 | 21.3 | 2.77 | 2.77 | 3.73 | 3.73 | 4.78 | 7.47 |
| ¾″ | 20 | 26.7 | 2.87 | 2.87 | 3.91 | 3.91 | 5.56 | 7.82 |
| 1″ | 25 | 33.4 | 3.38 | 3.38 | 4.55 | 4.55 | 6.35 | 9.09 |
| 1¼″ | 32 | 42.2 | 3.56 | 3.56 | 4.85 | 4.85 | 6.35 | 9.70 |
| 1½″ | 40 | 48.3 | 3.68 | 3.68 | 5.08 | 5.08 | 7.14 | 10.15 |
| 2″ | 50 | 60.3 | 3.91 | 3.91 | 5.54 | 5.54 | 8.74 | 11.07 |
| 2½″ | 65 | 73.0 | 5.16 | 5.16 | 7.01 | 7.01 | 9.53 | 14.02 |
| 3″ | 80 | 88.9 | 5.49 | 5.49 | 7.62 | 7.62 | 11.13 | 15.24 |
| 3½″ | 90 | 101.6 | 5.74 | 5.74 | 8.08 | 8.08 | — | 16.15 |
| 4″ | 100 | 114.3 | 6.02 | 6.02 | 8.56 | 8.56 | 13.49 | 17.12 |
| 5″ | 125 | 141.3 | 6.55 | 6.55 | 9.53 | 9.53 | 15.88 | 19.05 |
| 6″ | 150 | 168.3 | 7.11 | 7.11 | 10.97 | 10.97 | 18.26 | 21.95 |
| 8″ | 200 | 219.1 | 8.18 | 8.18 | 12.70 | 12.70 | 23.01 | 22.23 |
| 10″ | 250 | 273.1 | 9.27 | 9.27 | 12.70 | 15.09 | 28.58 | 25.40 |
| 12″ | 300 | 323.9 | 9.53 | 10.31 | 12.70 | 17.48 | 33.32 | 25.40 |
| 14″ | 350 | 355.6 | 9.53 | 11.13 | 12.70 | 15.09 | 35.71 | — |
| 16″ | 400 | 406.4 | 9.53 | 12.70 | 12.70 | 16.66 | 40.49 | — |
| 18″ | 450 | 457.0 | 9.53 | 14.27 | 12.70 | 19.05 | 45.24 | — |
| 20″ | 500 | 508.0 | 9.53 | 15.09 | 12.70 | 20.62 | 50.01 | — |
| 24″ | 600 | 610.0 | 9.53 | 17.48 | 12.70 | 24.61 | 59.54 | — |
STD = Standard weight, XS = Extra Strong, XXS = Double Extra Strong. Sch 40 equals STD and Sch 80 equals XS up to NPS 10 and NPS 8 respectively; above that they differ.
Tubes
Tube Sizes & BWG Wall Gauges
Tubes are ordered by actual outside diameter and wall thickness — in mm, inches or Birmingham Wire Gauge (BWG).
A Common Tube OD Sizes
| Inch | OD (mm) |
|---|---|
| ¼″ | 6.35 |
| ⅜″ | 9.53 |
| ½″ | 12.70 |
| ⅝″ | 15.88 |
| ¾″ | 19.05 |
| ⅞″ | 22.23 |
| 1″ | 25.40 |
| 1¼″ | 31.75 |
| 1½″ | 38.10 |
| 2″ | 50.80 |
B BWG Wall Thickness
| Gauge | Inch | mm |
|---|---|---|
| BWG 7 | 0.180 | 4.57 |
| BWG 8 | 0.165 | 4.19 |
| BWG 9 | 0.148 | 3.76 |
| BWG 10 | 0.134 | 3.40 |
| BWG 11 | 0.120 | 3.05 |
| BWG 12 | 0.109 | 2.77 |
| BWG 13 | 0.095 | 2.41 |
| BWG 14 | 0.083 | 2.11 |
| BWG 15 | 0.072 | 1.83 |
| BWG 16 | 0.065 | 1.65 |
| BWG 17 | 0.058 | 1.47 |
| BWG 18 | 0.049 | 1.24 |
| BWG 19 | 0.042 | 1.07 |
| BWG 20 | 0.035 | 0.89 |
| BWG 21 | 0.032 | 0.81 |
| BWG 22 | 0.028 | 0.71 |
| BWG 23 | 0.025 | 0.64 |
| BWG 24 | 0.022 | 0.56 |
Tube wall may be specified as minimum or average. Confirm which applies — and the tolerance — when you order.