JIS G3452 and G3454 Pipe Dimensions

What the Two Standards Cover

These are Japan’s two carbon-steel piping series, and they are not interchangeable. JIS G3452:2019 is ordinary piping, designation SGP: water, oil, gas and air at low pressure, with exactly one wall thickness at each size — 24 sizes, 24 walls, no schedule number anywhere. JIS G3454:2019 is pressure-service piping and publishes 105 walls at 25 diameters, sorted into 6 schedules.

They do not even carry the same size list. 190.7 and 241.8 mm — the sizes sold as 190.7 mm and 241.8 mm — appear only in G3452. 558.8, 609.6, 660.4 mm appear only in G3454, which runs three sizes larger at the top. A drawing that says only “JIS” has not finished specifying the pipe.

Region: Japan, and by adoption Korea and Taiwan. The country table compiled for this site maps 9 of 157 countries to the JIS family. Sizes are designated in A, the metric series used throughout this page, and in B, the inch series.

JIS G3452 SGP Dimensions

All 24 rows verified. Both mass columns are printed because the agreement between them is the verification: the published figure comes from the standard, the computed one from M = (OD - t) * t * C, and a mistyped wall thickness would show up as a mismatch.

JIS G3454 Schedule Dimensions

105 rows. 45 of them rest on one publisher and are marked single source in the last column — every row at schedule 10, schedule 20, schedule 30 is in that position. No source we found publishes a mass column for this standard, so every mass here is computed.

The size column shows a dash at 558.8, 609.6, 660.4 mm because the compiled size map runs to 500A and no further. Those diameters are published; the A designation for them is not something we could source, so it is left out rather than guessed.

Where JIS Parts From ASME B36.10M

Only 5 of the 27 Japanese diameters — 101.6, 114.3, 355.6, 406.4, 508 mm — appear in ASME B36.10M unchanged. Everything else differs, mostly by a few tenths, and at six sizes by millimetres.

The interesting part is what happens when the same schedule number is applied to those different diameters. Across the 22 trade sizes where both standards publish a schedule 40 wall, the two walls never differ by more than 0.05 mm. The bore does: 6 of the 22 pairs are at least 1 mm apart inside, and at DN 250 the gap reaches 5.66 mm.

Two consequences follow, and neither is visible from the schedule number. A JIS DN 65 pipe is 73 mm across in America and 76.3 mm in Japan, so nothing threads or welds between them; and identical walls on a smaller diameter mean a different pressure rating, in the Japanese pipe’s favour. If you are working from a drawing rather than a pipe, NPS to DN conversion resolves the designation first. Note that 2 of the 22 pairs behind those figures rest on a single publisher on the Japanese side, at 10.5 mm and 13.8 mm.

What We Could Verify, and What We Could Not

Of the 129 rows on this page, 84 are verified and 45 rest on a single publisher. Nothing had to be marked as could not be verified, and no published mass had to be suppressed.

The split is not evenly spread, and where it falls matters more than the ratio. All 24 G3452 rows come from the standard text and every one re-derives from its own published mass. In G3454, every row at schedule 10, schedule 20, schedule 30 is single-source, along with 12 rows in the heavier schedules at the extremes of the size range. Those are usable numbers, and they are labelled on every row that shows them.

The JIS table was also the one that forced a change of method. It is laid out column-major, the exact arrangement that made a language model misread the ASME table by reading down the wrong axis, so the pairing of each diameter to each wall was proved with the mass formula rather than read off the page. How this data was verified sets that out, and corrections we have made to our own data records what it caught.

The Same Sizes Under Other Standards

ASME B36.10M pipe dimensions

where the schedule numbers on this page came from

EN 10220 pipe dimensions

Europe — 76.1 mm at DN 65, against Japan’s 76.3

GOST pipe dimensions

Russia and the CIS — 76 mm at the same size, and no DN column

GB/T 17395 pipe dimensions

China — 76 mm as well, arrived at independently

For all of them side by side, see the pipe standards compared by country. For the American series in inches, steel pipe sizes, and for what a schedule number does and does not fix, schedule 40 pipe dimensions.

Frequently Asked Questions

What is the difference between JIS G3452 and G3454?

JIS G3452:2019 is the ordinary piping standard, designation SGP: it publishes one wall thickness per size, 24 rows in all. JIS G3454:2019 is the pressure-service standard and publishes 105 walls under schedule numbers 10, 20, 30, 40, 60, 80. They do not even cover the same sizes: 190.7 and 241.8 mm appear only in G3452, and 558.8, 609.6, 660.4 mm only in G3454.

Is JIS schedule 40 the same as ASME schedule 40?

The wall is. Across the 22 trade sizes where both standards publish a schedule 40 wall, the two walls never differ by more than 0.05 mm. The diameters are not the same, so the bore is not either: at DN 250 the Japanese pipe runs 5.66 mm narrower inside than the American one carrying the same schedule number.

What does SGP mean on Japanese pipe?

SGP is the designation JIS G3452 gives to ordinary piping — water, oil, gas and air at low pressure. It carries no schedule number because there is only one wall at each size: 24 sizes, 24 walls. Anything with a schedule number on it is G3454 pressure-service pipe.

Is Korean pipe the same as Japanese pipe?

Only half of it. KS D3562 reproduces JIS G3454 cell for cell. KS D3507 keeps the Japanese diameters but uses the BS 1387 and ISO 65 medium-series walls instead, so at 65A it is 3.65 mm against the Japanese 4.2 mm — a 13 per cent difference in wall on a pipe of identical outside diameter. Both Korean standards are paywalled, so those figures rest on distributor tables rather than on the standard, and are not published as verified anywhere on this site.

How much does JIS pipe weigh per metre?

Every mass on this page is computed from M = (OD - t) * t * C, with C = 0.02466 kg per metre for carbon steel. The 24 G3452 rows also carry a published mass, and all of them re-derive from that formula — which is what makes the pairing of diameter to wall in that table proved rather than assumed.