Standard · welded and seamless steel pipe
ASME B36.10M
Welded and seamless wrought steel pipe. OD is fixed per size; the wall (schedule) is what you choose.
- Sizes published
- 17
- Values published
- 128
- Wall series
- 13
- Size range
- 1/8–12
What is in this table
Outer diameter and wall thickness for NPS sizes in the range above, in inches and millimetres, with the bore derived as OD − 2 × wall. The chart is the working page: ASME B36.10M chart. Individual sizes have their own pages with sources listed per value.
- NPS 1/8 — OD 10.287 mm, DN 6 · 4 wall series
- NPS 1/4 — OD 13.716 mm, DN 8 · 4 wall series
- NPS 3/8 — OD 17.145 mm, DN 10 · 4 wall series
- NPS 1/2 — OD 21.336 mm, DN 15 · 7 wall series
- NPS 3/4 — OD 26.67 mm, DN 20 · 7 wall series
- NPS 1 — OD 33.401 mm, DN 25 · 7 wall series
- NPS 1 1/4 — OD 42.164 mm, DN 32 · 6 wall series
- NPS 1 1/2 — OD 48.26 mm, DN 40 · 7 wall series
- NPS 2 — OD 60.325 mm, DN 50 · 7 wall series
- NPS 2 1/2 — OD 73.025 mm, DN 65 · 6 wall series
- NPS 3 — OD 88.9 mm, DN 80 · 7 wall series
- NPS 4 — OD 114.3 mm, DN 100 · 8 wall series
- NPS 5 — OD 141.3 mm, DN 125 · 7 wall series
- NPS 6 — OD 168.275 mm, DN 150 · 8 wall series
- NPS 8 — OD 219.075 mm, DN 200 · 13 wall series
- NPS 10 — OD 273.05 mm, DN 250 · 13 wall series
- NPS 12 — OD 323.85 mm, DN 300 · 13 wall series
What is deliberately not here
These designations appear in at least one source for some size but were not confirmed by a second independent source, so they are recorded as unverified instead of published: 10, 30, 60. A missing value is not a wrong value — it is a value we did not earn.
A further 17 size × designation value(s) in this series are held back (one source only, or sources disagreeing). The published index reports those counts — a gap is information, a silence is not.
No revision year is claimed. We know these values match ASME B36.10M as published by the sources listed on the size pages, but the specific edition was not verified — so nothing here says “ASME B36.10M-2018” or any other year.
How each number got here
- Two independent published sources must print the same value.
- The value is parsed from the source's own table, not retyped by hand.
- Millimetres are derived from the inch value × 25.4 (exact), never copied from a third table.
- Bore is computed as OD − 2 × wall and labelled exact or maximum.
- Conflicts are kept and reported, not deleted. Full policy.
Not a substitute for the standard. ASME and ASTM documents carry tolerances, materials and pressure classes that this page does not reproduce. Use it to identify a size and to check a number, not to approve a design.