About pipesizechart.com
A reference for pipe dimensions — outside diameter, wall thickness, inside diameter and mass — where every figure states which standard it came from and whether it could be verified.
Why This Site Exists
Pipe charts are mostly copies of copies. Compiling this data meant reading thirteen publishers, and roughly twenty-five errors turned up across them; every publisher checked carried at least one. Two of those errors are outside diameters (OD) on a chart that ranks on the first page of Google for the term this site is built around, and one of them is a European figure printed in a table labelled American.
So the gap is not another table. It is a table that says where each number came from, which figures agree with the standard’s own arithmetic, and which ones could not be confirmed at all.
What Is Here
The main chart is ASME B36.10M-2015: 766 of 772 rows verified against the standard itself rather than against another chart. Behind it sits a wider compilation — nine steel outside-diameter series covering the United States, Europe, Japan, Korea, Russia and China, 164 DN-to-OD values, plus copper across six national standards and the plastic series. Pages are published as each series clears the same check, not before.
How the Numbers Get Here
- Parsed from the standard, never retyped
- Every table is read programmatically from the source document — regular expressions over raw HTML, PDF x-coordinates, pdftotext -layout. Nothing here was typed in by hand, and no language model is allowed to read a table for numbers. That was tried; it failed three times, once inventing rows for sizes the page did not contain, and the output was discarded.
- Checked against the standard’s own mass formula
- Each standard publishes a relationship between outside diameter, wall thickness and mass per unit length: M = (OD − t) × t × C. Recomputing every published mass tests all three numbers against each other at once, so a mistyped wall thickness stops matching and the row fails. It is the standards’ own arithmetic, not ours — and it caught errors that reading never would.
- Anything unverifiable is labelled, not dropped
- Every row carries a publication status. A figure that could not be confirmed is shown with a visible “could not be verified” label, or left out — never presented as fact. Saying what could not be verified is the product, not an admission.
- Cross-standard divergence is the main event
- Most charts publish one standard and imply it is the answer. Nine steel outside-diameter series were compiled side by side — ASME, EN, JIS, KS, GOST and GB/T — because the same designation resolves to different pipe. At DN 65 every other standard says about 76 mm; ASME alone says 73.0. At DN 125 the rest say 139.7 to 140; ASME says 141.3.
Who Builds It
The tables here are compiled and maintained by the pipesizechart team. It is an independent reference: not published by a standards body, a manufacturer or a distributor, not sponsored, and nothing on it is for sale — so no figure on the site is chosen to suit anyone’s catalogue.
The dimensions published here were validated by the team before they went up — not read off another chart and reprinted. Every table is parsed from the standard itself, the raw source documents are archived so any figure can be re-derived years later, and each figure is put through the checks below.
The team does not put names, photographs or job titles on these pages, and it will not claim credentials it cannot show you. What can be audited is not a name but a method — and the failures are published too, including this project’s own parser bugs, which cost four common sizes before anyone noticed. That record is the list of errors found in published pipe data, and in ours.
- Every mass recomputed, row by row
- All 772 rows were put back through the standard's own relationship between diameter, wall and mass — M = (OD − t) × t × C. That tests three numbers against each other at once, so a single mistyped wall stops matching. 766 rows clear it against the standard itself.
- Every schedule label re-derived and compared
- Labels are not numbers, and arithmetic is blind to them: thirty-nine wrong schedule designations once passed the mass check untouched. So the designations are re-derived from source and diffed against what is published, as a separate check with its own script.
- Anything the team could not confirm is labelled
- Validation that only reports its successes is not validation. Rows that could not be confirmed carry a visible “could not be verified” label or are held out of the table entirely, and of the 157 country entries only 16 were checked against the national standard itself — the other 141 say so on the page.
What This Site Is Not
- Not a calculator
- It does not size pipe for flow, pressure drop or code compliance. That is a different problem with different inputs, and the answer depends on a code this site does not reproduce. What is here is dimensional: what a given designation physically measures.
- Not a supplier
- Nothing is for sale. There is no stock, no quotation and no distributor behind the tables, so no figure here is chosen to suit anyone’s catalogue.
- Not affiliated with any standards body
- ASME B36.10M is a standard of the American Society of Mechanical Engineers. EN, ISO, JIS, KS, GOST and GB/T belong to their own bodies. This site is independent of all of them and reproduces dimensional facts only.
- Not a substitute for the standard
- Where a figure carries contractual or safety weight, buy the standard. Every published chart checked during compilation — including the ones this site was built from — carried at least one error.
What Is Missing, and What Each Gap Is Waiting On
Every dimension dataset compiled so far is steel. That leaves 5 material pages the site would obviously want, absent for one reason: writing them would mean inventing numbers. Each is waiting on a particular document rather than on time, so the gap is nameable.
- PVC
- Waiting on ASTM D1785 / D2241, parsed and mass-checked the way the steel data was.
- Copper
- Waiting on ASTM B88 and EN 1057, parsed and mass-checked the way the steel data was.
- HDPE
- Waiting on ISO 4427 / ASTM F714, parsed and mass-checked the way the steel data was.
- Ductile iron
- Waiting on ISO 2531 / AWWA C151, parsed and mass-checked the way the steel data was.
- Cast iron
- Waiting on EN 877 / ASTM A74, parsed and mass-checked the way the steel data was.
One further candidate, black steel, is deliberately absent for the opposite reason. It is uncoated carbon steel on the same dimensional series as the steel pages already here, so a page of its own would be duplicate content rather than a missing one. The stainless table is published but rests on a single publisher, and says so on the page instead of being presented at the confidence of the carbon steel it sits beside.
One editorial rule governs all of this. Publishers whose figures turned out to be wrong are described here, never named: the claim being made is about a number, not about a company, and a number is something a reader can go and check.
Reporting an Error
If a figure here is wrong, the useful report names the standard and its edition, the table or clause, the size, and the value you believe it should be. A report that says where your figure comes from can be checked in minutes; one that does not usually cannot be checked at all.
Reports go to info@pipesizechart.com, and every one is tested the way the original data was: against the standard’s own mass formula, and against the standard’s text where it is obtainable. If it holds, the change is published with a date. Nothing is edited silently.
The full method — the sources, the arithmetic, and the list of figures that could not be confirmed — is set out in how this data was verified. The dimensions themselves start at the pipe size chart. Data revision: .