REFERENCE · EN 1092-1

EN 1092-1 material groups (1E0 to 16E0)

EN 1092-1 · EN 1092-1:2018 · verified 2026-11-04

Pressure-temperature ratings Material groups Tolerances Marking Types and facings

Reference tables are transcribed from EN 1092-1:2018; table numbers, printed page numbers and cell values keep the standard's original wording.

EN 1092-1 sorts flange steels into material groups rather than individual grades. A group collects materials with similar chemical and mechanical properties and similar corrosion resistance, so one pressure–temperature rating can be applied to any member of the group. The definitions are in informative Annex B, and the material selection table (Table 9) maps each group to EN forging, flat-product, casting and bar grades.

Group codes combine a family number, the letter E and a sub-index — 3E0, 6E1, 13E0 and so on. The numbering broadly follows the steel family described in Annex B (carbon, low-alloy, low-temperature, fine-grain, high-temperature ferritic or austenitic), and the trailing digit separates variants within that family. Confirm the group from the grade actually certified: an offered 1.4404 flange is group 13E0, not 14E0, even though both are molybdenum-bearing austenitic steels.

Two caveats matter for procurement. Table 9 is a selection for flange manufacture, not a list of every acceptable steel; Annex D adds materials, including ASME grades, that are widely used but not listed in EN standards, and those carry no presumption of conformity under the Pressure Equipment Directive. And a p/T rating quoted for a group is valid only for materials that genuinely belong to it — the certificate or material test report is the evidence.

Groups1E0 to 16E0

Group definitionsAnnex B (informative)

Material selectionTable 9 (pp. 38–43)

Additional materialsAnnex D (pp. 101–102)

p/T ratingsAnnex G (selected groups)

Non-austenitic groups 1E0 to 9E1

The carbon, low-alloy, low-temperature, fine-grain and high-temperature ferritic groups as defined in Annex B, with representative EN grades from Table 9.

Material groups 1E0 to 9E1 — Annex B definitions with typical EN grades from Table 9 / Annex D (pp. 89–90, 38–40, 101)

Group	What the group covers (Annex B)	Typical EN grades (material number)	Notes
1E0	Unalloyed structural steels without guaranteed elevated-temperature properties; application range −10 °C to +100 °C.	GS-38 casting (1.0432, DIN 1681); VdTÜV C 21/1.0432	Annex D additional material; no Annex G p/T table.
1E1	Unalloyed structural steels with elevated-temperature properties.	S235JR (1.0038) to EN 10025-2	Annex D additional material; no Annex G p/T table.
3E0	Unalloyed steels with guaranteed elevated-temperature properties.	P250GH (1.0460) and P245GH (1.0352), EN 10222-2 forgings; P235GH (1.0345) and P265GH (1.0425), EN 10028-2 flats; GP240GH (1.0619) and GP280GH (1.0625), EN 10213 castings	p/T: Tables G.2–G.13 (calculated for P245GH). Default group for EN 1092-1 carbon-steel flanges.
3E1	Unalloyed steels with specified properties up to 400 °C and upper yield strength above 265 N/mm².	P280GH (1.0426), EN 10222-2; P295GH (1.0481), EN 10028-2	p/T: Tables G.2–G.13 (P280GH).
4E0	Low-alloyed steels with 0,3 % molybdenum.	16Mo3 (1.5415), EN 10222-2 / EN 10028-2; G20Mo5 (1.5419), EN 10213	p/T: Tables G.2–G.13 (16Mo3).
5E0	Low-alloyed steels with 1 % chromium and 0,5 % molybdenum.	13CrMo4-5 (1.7335), EN 10222-2 / EN 10028-2; G17CrMo5-5 (1.7357), EN 10213	p/T: Tables G.2–G.13 (13CrMo4-5).
6E0	Low-alloyed steels with 2 % chromium and 1 % molybdenum.	11CrMo9-10 (1.7383), EN 10222-2; 10CrMo9-10 (1.7380) and 12CrMo9-10 (1.7375), EN 10028-2; G17CrMo9-10 (1.7379), EN 10213	p/T: Tables G.2–G.13 (11CrMo9-10).
6E1	Alloy steel with 5 % chromium and 0,5 % molybdenum.	X16CrMo5-1+NT (1.7366), EN 10222-2; GX15CrMo5 (1.7365), EN 10213	p/T: Tables G.2–G.13 (X16CrMo5-1+NT).
7E0	Low-temperature-tough fine-grain steel with minimum yield strength 275 N/mm² at room temperature.	P275NL1 (1.0488) and P275NL2 (1.1104), EN 10028-3 flats; G17Mn5 (1.1131) and G20Mn5 (1.6220), EN 10213 castings	No separate Annex G p/T table.
7E1	Low-temperature-tough fine-grain steel with minimum yield strength 355 N/mm² at room temperature.	P355NL1 (1.0566) and P355NL2 (1.1106), EN 10028-3	No separate Annex G p/T table.
7E2	Low-temperature nickel-alloyed steel with nickel ≤ 3 %.	15NiMn6 (1.6228), EN 10222-3; 11MnNi5-3 (1.6212) and 13MnNi6-3 (1.6217), EN 10028-4; G9Ni10 (1.5636), EN 10213	No separate Annex G p/T table.
7E3	Low-temperature nickel-alloyed steel with nickel > 3 %.	12Ni14 (1.5637), X12Ni5 (1.5680), X8Ni9 (1.5662), EN 10222-3 / EN 10028-4; G9Ni14 (1.5638), EN 10213	No separate Annex G p/T table.
8E0	Fine-grain steel with minimum yield strength 225 N/mm² at room temperature.	No grade listed in Table 9 for this group	Defined in Annex B; no grade or p/T table in the 2018 edition.
8E2	Fine-grain steel with minimum yield strength 285 N/mm² at room temperature.	P285NH (1.0477) and P285QH (1.0478), EN 10222-4; P275NH (1.0487), EN 10028-3 / EN 10273	p/T: Tables G.2–G.13 (P285NH).
8E3	Fine-grain steel with minimum yield strength 355 N/mm² at room temperature.	P355NH (1.0565) and P355QH1 (1.0571), EN 10222-4; P355N (1.0562) and P355NH (1.0565), EN 10028-3; P355QH (1.8867), EN 10273	p/T: Tables G.2–G.13 (P355NH).
9E0	High-temperature-tough ferritic steel with 12 % chromium, 1 % molybdenum and 0,5 % vanadium.	X20CrMoV11-1 (1.4922), EN 10222-2; GX23CrMoV12-1 (1.4931), EN 10213	p/T: Tables G.2–G.13 (X20CrMoV11-1).
9E1	High-temperature-tough ferritic steel with 9 % chromium, 1 % molybdenum, 0,25 % vanadium and 0,1 % niobium.	X10CrMoVNb9-1 (1.4903), EN 10222-2 / EN 10028-2	p/T: Tables G.2–G.13 (X10CrMoVNb9-1).

Descriptions paraphrase informative Annex B. Grade and material-number examples are taken from Table 9 (forgings, flat products, castings and bars) and, for 1E0/1E1, from informative Annex D. One grade is enough to place a flange in a group; always confirm the group from the material certificate.

Austenitic and austenitic-ferritic groups 10E0 to 16E0

Annex B notes that groups 10E0 to 12E0 are not alloyed with molybdenum, while 13E0 to 15E0 are; 16E0 is the austenitic-ferritic (duplex) family.

Austenitic and austenitic-ferritic groups 10E0 to 16E0 — Annex B definitions with typical EN grades (pp. 90, 39–40, 43)

Group	What the group covers (Annex B)	Typical EN grades (material number)	Notes
10E0	LC-steel (low-carbon austenitic).	X2CrNi18-9 (1.4307), EN 10222-5 forgings; X2CrNi19-11 (1.4306) flat; GX2CrNi19-11 (1.4309), EN 10213	p/T: Tables G.15–G.26 (1.4307).
10E1	LC-steel, nitrogen-alloyed.	X2CrNi18-10 (1.4311), EN 10222-5	p/T: Tables G.15–G.26 (1.4311).
11E0	Austenitic, standard carbon content.	X5CrNi18-10 (1.4301) and X6CrNi18-10 (1.4948), EN 10222-5; GX5CrNi19-10 (1.4308), EN 10213	p/T: Tables G.15–G.26 (1.4301, 1.4948).
12E0	Austenitic, standard carbon content, stabilised with Ti or Nb.	X6CrNiTi18-10 (1.4541), X6CrNiNb18-10 (1.4550) and X6CrNiTiB18-10 (1.4941), EN 10222-5; GX5CrNiNb19-11 (1.4552), EN 10213	p/T: Tables G.15–G.26 (1.4541, 1.4550, 1.4941).
13E0	LC-steel with molybdenum.	X2CrNiMo17-12-2 (1.4404), X2CrNiMo17-12-3 (1.4432) and X2CrNiMo18-14-3 (1.4435), EN 10222-5; GX2CrNiMo19-11-2 (1.4409), EN 10213	p/T: Tables G.15–G.26 (1.4404).
13E1	LC-steel with molybdenum, nitrogen-alloyed.	X2CrNiMoN17-13-3 (1.4429), X2CrNiMoN17-13-5 (1.4439) and X2CrNiMoN17-11-2 (1.4406)	No separate Annex G p/T table in this edition.
14E0	Austenitic, standard carbon content, alloyed with molybdenum.	X5CrNiMo17-12-2 (1.4401) and X3CrNiMo17-13-3 (1.4436); GX5CrNiMo19-11-2 (1.4408), EN 10213	p/T: Tables G.15–G.26 (1.4401).
15E0	Austenitic, standard carbon content, alloyed with molybdenum, stabilised with Ti or Nb.	X6CrNiMoTi17-12-2 (1.4571) and X6CrNiMoNb17-12-2 (1.4580); GX5CrNiMoNb19-11-2 (1.4581), EN 10213	p/T: Tables G.15–G.26 (1.4571).
16E0	Austenitic-ferritic (duplex) steel.	X2CrNiMoN22-5-3 (1.4462), X2CrNiMoN25-7-4 (1.4410) and X2CrNiN23-4 (1.4362), EN 10222-5; GX2CrNiMoN25-6-3-3 (1.4517), EN 10213	p/T: Tables G.15–G.26 (1.4462).

Descriptions paraphrase informative Annex B. Grades come from Table 9; the material number in brackets in the Notes column is the one used in the Annex G p/T tables (Table G.14, p. 125).

Which groups have pressure–temperature ratings?

Not every group in Annex B appears in the Annex G rating tables. The coverage is:

Non-austenitic: 3E0, 3E1, 4E0, 5E0, 6E0, 6E1, 8E2, 8E3, 9E0 and 9E1, in Tables G.2 to G.13.
Austenitic: the eleven materials listed in Table G.14 — 1.4307, 1.4311, 1.4301, 1.4541, 1.4550, 1.4404, 1.4401, 1.4571, 1.4462, 1.4948 and 1.4941 — in Tables G.15 to G.26.
1E0 and 1E1 appear only as additional materials in Annex D and have no Annex G p/T table.
The 7E0 to 7E3 low-temperature groups are defined in Annex B but are not assigned separate p/T tables.
8E0 is defined in Annex B, but Table 9 lists no grade for it in the 2018 edition.

FAQ

Which material group is P250GH?: P250GH (1.0460, EN 10222-2) is group 3E0, the unalloyed steel group with guaranteed elevated-temperature properties. P245GH (1.0352) is also 3E0; P280GH (1.0426) is group 3E1.
Which group is 1.4301?: 1.4301 (X5CrNi18-10) is group 11E0 — austenitic steel with standard carbon content and no molybdenum. The low-carbon variant 1.4307 (X2CrNi18-9) is group 10E0.
Which group is 1.4404?: 1.4404 (X2CrNiMo17-12-2) is group 13E0 — low-carbon austenitic steel with molybdenum. The standard-carbon 1.4401 (X5CrNiMo17-12-2) is group 14E0.
Can I substitute one grade for another in the same group?: The grouping exists so that materials with similar properties can be treated equivalently for pressure, temperature and fluid service, and a group-level p/T rating is intended to cover its members. It does not make grades interchangeable in every detail — corrosion resistance, impact toughness and elevated-temperature strength can still differ. The material certificate and the project specification decide.

Sources

EN 1092-1:2018, Annex B — Material groups (pp. 89–90)
EN 1092-1:2018, Table 9 — Material selection for the manufacturing of flanges (pp. 38–43)
EN 1092-1:2018, Annex D — Additional materials (pp. 101–102)
EN 1092-1:2018, §5.1.1 — Materials (p. 13)
EN 1092-1:2018, Table G.1 (p. 112) and Table G.14 (p. 125)

EN 1092-1:2018 (PDF supplied for this project)