Guide
Pipe schedule chart: SCH 40, 80, 160 and XXS in mm
Outside diameter and wall thickness for steel pipe from ½" to 24" (22" not listed), with weight per metre for SCH 40 and SCH 80 carbon steel pipe.
How to read the chart
The nominal pipe size (NPS) is a name, not a measurement. For every NPS the outside diameter stays the same, and the schedule sets the wall thickness. A higher schedule means a thicker wall and a smaller bore.
From 8" upwards, XXS is thinner than SCH 160, so do not assume XXS is always the heaviest wall.
Pipe schedule chart (mm)
| NPS | OD (mm) | SCH 40 wall (mm) | SCH 80 wall (mm) | SCH 160 wall (mm) | XXS wall (mm) | SCH 40 (kg/m) | SCH 80 (kg/m) |
|---|---|---|---|---|---|---|---|
| ½″ | 21.3 | 2.77 | 3.73 | 4.78 | 7.47 | 1.27 | 1.62 |
| ¾″ | 26.7 | 2.87 | 3.91 | 5.56 | 7.82 | 1.69 | 2.20 |
| 1″ | 33.4 | 3.38 | 4.55 | 6.35 | 9.09 | 2.50 | 3.24 |
| 1¼″ | 42.2 | 3.56 | 4.85 | 6.35 | 9.70 | 3.39 | 4.47 |
| 1½″ | 48.3 | 3.68 | 5.08 | 7.14 | 10.15 | 4.05 | 5.41 |
| 2″ | 60.3 | 3.91 | 5.54 | 8.74 | 11.07 | 5.44 | 7.48 |
| 2½″ | 73.0 | 5.16 | 7.01 | 9.53 | 14.02 | 8.63 | 11.41 |
| 3″ | 88.9 | 5.49 | 7.62 | 11.13 | 15.24 | 11.29 | 15.27 |
| 4″ | 114.3 | 6.02 | 8.56 | 13.49 | 17.12 | 16.07 | 22.32 |
| 5″ | 141.3 | 6.55 | 9.53 | 15.88 | 19.05 | 21.77 | 30.97 |
| 6″ | 168.3 | 7.11 | 10.97 | 18.26 | 21.95 | 28.26 | 42.56 |
| 8″ | 219.1 | 8.18 | 12.70 | 23.01 | 22.23 | 42.55 | 64.64 |
| 10″ | 273.0 | 9.27 | 15.09 | 28.58 | 25.40 | 60.29 | 95.97 |
| 12″ | 323.8 | 10.31 | 17.48 | 33.32 | 25.40 | 79.70 | 132.04 |
| 14″ | 355.6 | 11.13 | 19.05 | 35.71 | – | 94.55 | 158.10 |
| 16″ | 406.4 | 12.70 | 21.44 | 40.49 | – | 123.30 | 203.53 |
| 18″ | 457.0 | 14.27 | 23.83 | 45.24 | – | 155.80 | 254.55 |
| 20″ | 508.0 | 15.09 | 26.19 | 50.01 | – | 183.42 | 311.17 |
| 24″ | 610.0 | 17.48 | 30.96 | 59.54 | – | 255.41 | 442.08 |
How the weight is worked out
Carbon steel weight in kg/m = (OD − wall) × wall × 0.02466, with OD and wall in mm, rounded to 2 decimals.
These values are nominal, per ASME B36.10M. Wall thickness has a mill tolerance, so confirm the actual dimensions against the mill certificate before you design or weld to them.
Matching fittings to the pipe
Butt-weld fittings should match the pipe schedule so the bores line up for welding. We list S.S butt-weld fittings in SCH10, SCH40 and SCH80, C.S butt-weld fittings in SCH STD to SCH160, forged threaded fittings in CL1000 to CL6000 and forged socket-weld fittings in 2000, 3000 and 6000 psi. Send your sizes and schedules on WhatsApp for a quote.
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Questions buyers ask
Is SCH 40 the same as STD?
Up to 10" they share the same wall thickness. Above that they differ, so always state the schedule you need.
Why is XXS thinner than SCH 160 at 8" and above?
XXS and the numbered schedules come from different series. From 8" upwards SCH 160 has the thicker wall.
Do you stock these pipes?
We list M.S pipe, ERW and seamless, in SCH STD, SCH40, SCH80 and SCH160 from ½" to 12", S.S pipe in SCH10, SCH40 and SCH80 from ¼" to 12", and G.I pipe from ½" to 6". Send the size and schedule on WhatsApp.
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Sizes, rating, end connection and quantity. We reply with stock and a price.