EN 10365 is the European standard that defines the nominal dimensions and masses of hot rolled steel I sections, H sections and channels. Published by CEN in January 2017, it replaced the long-standing German standards DIN 1025 (beams) and DIN 1026 (channels), and brought several British profile families into the same document. This article covers what EN 10365 actually contains, what changed against the DIN, which tolerance standards still apply, and how the norm is treated for stainless steel structural sections.
What Is EN 10365?
The full title of the standard is “Hot rolled steel channels, I and H sections – Dimensions and masses”. It is published by the European Committee for Standardization (CEN) through technical committee CEN/TC 103 and applies to hot rolled carbon steel sections. The standard sets the nominal cross-section geometry and mass per metre, but it does not specify tolerances, internal/external radii or section properties, which are covered by separate documents.
EN 10365 unified two scopes that used to live in separate norms — beams and channels — and added the British UB, UC, HP/UBP, HD, HL/HLZ, PFC and J series, which were never part of the DIN tradition. The current version is EN 10365:2017; a revision is currently in committee work at CEN level.
From DIN 1025 and DIN 1026 to EN 10365
Before EN 10365, structural sections in continental Europe were defined by two German standards issued by the Deutsches Institut für Normung (DIN), the national standards body of Germany since 1917. Both norms were first released in 1926 and went through several revisions before being superseded by the European standard.
DIN 1025 — Five Families of Structural Beams
DIN 1025 defined I and H sections in five parts. The last revision was issued in 1995.
- DIN 1025-1 — IPN (also INP). I-beams with taper internal flanges. 20 sizes, height from 80 to 550 mm. Less common today because the conical flange complicates connections.
- DIN 1025-2 — HEB (originally IPB). Wide flange H-beams with parallel flanges. 24 sizes, 100 to 1000 mm. The most widely used heavy section in European construction.
- DIN 1025-3 — HEA (IPBl). Lighter version of the HEB. 24 sizes, 100 to 1000 mm.
- DIN 1025-4 — HEM (IPBv). Heavy version of the H series for high loads. 24 sizes, 100 to 1000 mm.
- DIN 1025-5 — IPE. I-beams with parallel flanges, lighter than the IPN. 18 sizes, 80 to 600 mm. The reference profile for most European steel construction.
DIN 1026 — Channels
DIN 1026 covered hot rolled channels in two parts. The last version is dated 2009-09.
- DIN 1026-1 — UPN (also UNP). Channels with taper internal flanges. 27 sizes, height 30 to 400 mm. The classic European channel.
- DIN 1026-2 — UPE. Channels with parallel flanges. 14 sizes, 80 to 400 mm. Heights match the IPE family, which makes UPE and IPE easy to combine in the same structure.
What Changed with EN 10365?
Three substantive changes are worth noting for designers and procurement:
- Beams and channels are now in one document. EN 10365 collapses what used to be two separate DIN families.
- British profiles are included. UB, UC, PFC, HD, HL/HLZ, HP/UBP and J sections are now part of the same European reference.
- No internal or external radii, no section properties. Unlike the DIN, EN 10365 does not fix the corner radii (which can vary between mills) and does not list moments of inertia, section moduli or radii of gyration. Designers take those from the producer’s datasheet or from Eurocode-aligned section tables.
Sections Covered by EN 10365
The standard covers the shapes listed below, ordered from the most common in European projects to the more specialised but still widely used.
I and H Sections (Beams and Columns)
- IPE — Parallel flange I-beam. The European structural workhorse.
- HEA / HEB / HEM — Wide flange H-beams (light, medium, heavy). The standard column and heavy beam family in EU construction.
- HE-AA, HEC — Super-light and intermediate HE versions added in EN 10365 to widen the range.
- IPN / J — Taper flange I-beams. Older European geometries, still specified in retrofit work, mining and rail-related applications.
- UB — Universal beam (UK origin). Common in British and export markets.
- UC — Universal column (UK), the British equivalent of HE.
- HD — Wide flange column, heavy section with ArcelorMittal heritage.
- HP / UBP — Wide flange bearing piles for foundations and piling work.
- HL / HLZ — Extra wide flange beams for long spans and heavy industrial structures.
Channels (U and C Sections)
- UPE — Parallel flange channel. Heights matched to IPE; preferred for modern fabrication.
- UPN (UNP) — Taper flange channel. Classic European channel, still in heavy use across the industry.
- PFC — Parallel flange channel of British origin, equivalent in concept to the UPE.
- U / CH — Taper flange channels of country-specific legacy origin, less common today.
New Dimensions Added in EN 10365
EN 10365 widened the size range of the most-used families:
- IPE. Lighter IPE-A and IPE-AA versions, heavier IPE-O and IPE-V versions, and four additional sizes around IPE 750. Some mills also produce extra-light IPE-AAA and IPE-AAAA variants outside the norm.
- HE. A super-light HE-AA series, an intermediate HEC (lighter than HEM), plus 16 additional HE profiles defined only by height and mass per metre.
- UPN. Three small sizes were dropped (UNP 30×15×4×4.5, UNP 30×33×5×7, UNP 40×35×5×7), and one new size was added: UNP 40×20×4×5.5.
- UPE. Dimensions are unchanged from DIN 1026-2.
Tolerances: Which Standards Still Apply
EN 10365 sets nominal geometry only. Dimensional, shape and mass tolerances are governed by separate European standards, unchanged from the DIN era:
- EN 10034 — I and H sections with parallel flanges (IPE, HE, UB, UC, HD, HL, HLZ, HP).
- EN 10024 — Taper flange I sections (IPN, J).
- EN 10279 — Channels, both parallel and taper flange (UPE, UPN, PFC, U, CH).
What EN 10365 Does Not Cover: Angles and Tees
Angle bars and T-sections fall outside EN 10365 and have their own European norms:
- EN 10056-1 — Equal and unequal leg angle bars (dimensions); EN 10056-2 covers tolerances. This standard already replaced the older DIN 1028 and applies to both carbon and stainless steel.
- EN 10055 — Equal flange tees with radiused root and toes (dimensions and tolerances).
For non-standard tees, including wide flange tees obtained by splitting H-beams, dimensions are typically agreed with the producer.
Does EN 10365 Apply to Stainless Steel?
Strictly, no. The text states that the standard does not apply to hot rolled channels, I and H sections in stainless steel, the same disclaimer that appeared in the DIN. The reason is jurisdictional: CEN/TC 103 writes for carbon steel, while stainless steel falls under ECISS/TC 23.In practice, the stainless steel committee historically aligned with the DIN dimensions (DIN 1025 and DIN 1026 were the de facto reference for stainless beams and channels), and the same alignment now exists with EN 10365. The precedent is EN 10056, which superseded DIN 1028 for angle bars and is applied to both carbon and stainless steel without controversy.
Montanstahl produces stainless steel structural sections by hot rolling, cold rolling and laser welding to the dimensions defined in EN 10365. Order acknowledgements and material test certificates have referenced EN 10365 since February 2019. The change is purely formal: the geometry of the products supplied is unchanged. If a project requires particular internal or external radii, those must be specified at the order stage, since EN 10365 leaves them open.
Montanstahl Stock Range Under EN 10365
Montanstahl carries the following structural sections in stock, in stainless steel grades 1.4301, 1.4307, 1.4401, 1.4404 and 1.4571 (304, 304L, 316, 316L and 316Ti):
- IPE beams — EN 10365
- IPN beams — EN 10365
- HEA / HEB / HEM beams — EN 10365
- UPN (UNP) channels — EN 10365
- UPE channels — EN 10365
- UAP (UPA) channels — parallel flange, stainless-only series, tolerances per EN 10279
- Equal leg angles — EN 10056-1
- Unequal leg angles — EN 10056-1
- Equal flange tees — EN 10055
- Wide flange tees
Sizes and families outside this list — including American (W, S, MC, C), Asian (UB/UC, JIS) and tailored cross-sections — are produced on demand, including by laser welding when geometries fall outside the hot rolled range, and by hot extrusion for complex special profiles.
Conclusion: One Standard, Wider Coverage, Same Tolerances
EN 10365 is now the single dimensional reference for hot rolled steel I, H and channel sections in Europe. Tolerance standards remain unchanged, and the practical impact on existing designs is limited to the formal citation. The benefit is a wider catalog under one document, including British profiles, and a clearer path for stainless steel structural sections to use the same dimensional reference.
Key takeaways:
- EN 10365:2017 replaces DIN 1025 (beams) and DIN 1026 (channels) and adds British UB, UC, PFC, HD, HL/HLZ, HP/UBP and J sections
- The standard defines nominal dimensions and mass only, not tolerances, radii or section properties
- Tolerances are unchanged: EN 10034, EN 10024 and EN 10279 still apply
- Angles (EN 10056) and tees (EN 10055) remain governed by separate norms
- EN 10365 formally excludes stainless steel, but its dimensions are applied in practice to stainless structural sections, in line with the EN 10056 precedent
Specifying structural sections for a project, or sourcing stainless steel beams, channels, angles or tees to EN 10365 / EN 10056 / EN 10055? Contact us today to discuss stock availability, tailored sizes and delivery conditions.