SIST EN 1993-1-10:2025/oprA1:2026

• Abstract:

  1.1 Scope of EN 1993-1-10; (1) EN 1993-1-10 specifies rules for the selection of steel grades and qualities related to fracture toughness to avoid brittle fracture.; NOTE Steel quality is also known as (Charpy) subgrade.; (2) EN 1993-1-10 specifies rules to specify through thickness properties for welded elements to reduce the risk of lamellar tearing.; (3) EN 1993-1-10 specifies additional toughness requirements for specific cases to ensure upper shelf toughness in relation to design ultimate resistance in tension and seismic design.; (4) EN 1993-1-10 specifies rules for structural steels as listed in EN 1993-1-1. This document applies to steel grades S235 to S700.; (5) EN 1993-1-10 specifies rules that apply to the selection of parent material only.; (6) EN 1993-1-10 specifies rules that apply to steel materials covered by EN 1993-1-1:2022, 5.1(3), provided that each individual piece of steel is tested in accordance with the requirements of EN 1993 1 1:2022, 5.2.1 and EN 1090-2:2018+A1:2024, 5.1.; (7) This document does not apply to material salvaged from existing steelwork subjected to fatigue or fire.; 1.2 Assumptions; (1) Unless specifically stated, EN 1990, EN 1991 (all parts) and the other relevant parts of EN 1993-1 (all parts) apply.; (2) The design methods given in EN 1993-1-10 are applicable if:; - the execution quality is as specified in EN 1090-2 or EN 1090-4, and; - the construction materials and products used are as specified in the relevant parts of EN 1993 (all parts), or in the relevant material and product specifications.

• Status: Not Published
• Public Enquiry End Date: 29-Jul-2026
• ICS: 91.010.30 - Technical aspects
• ICS: 91.080.13 - Steel structures
• Technical Committee: KON - Structures
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 10-Jun-2026
• Due Date: 28-Oct-2026
• Ref Project: EN 1993-1-10:2025/prA1 - Eurocode 3 - Design of steel structures - Part 1-10: Material toughness and through-thickness properties

• Amends: kSIST FprEN 1993-1-10:2024 - Eurocode 3: Design of steel structures - Part 1-10: Material toughness and through-thickness properties
• Effective Date: 20-Jan-2026

SIST EN 1993-1-10:2025/oprA1:2026 is the Slovenian draft amendment to EN 1993-1-10:2025, published by SIST and prepared in CEN/TC 250. It concerns Eurocode 3 steel structures and gives rules for selecting steel grades and qualities for fracture toughness, specifying through-thickness properties to reduce lamellar tearing, and adding toughness rules for specific cases. It is intended for structural engineers, designers, fabricators and others who specify or check steel quality for welded steelwork.

What does SIST EN 1993-1-10:2025/oprA1:2026 specify?

SIST EN 1993-1-10:2025/oprA1:2026 is an amendment to EN 1993-1-10:2025, so its content is organized as changes to the base document. The amended standard covers the selection of steel quality to avoid brittle fracture, through-thickness properties for welded elements, and special toughness requirements for upper shelf toughness in tension and seismic design.

The scope applies to structural steels listed in EN 1993-1-1, for steel grades S235 to S700, and to parent material only. It also covers steel materials from EN 1993-1-1:2022, 5.1(3), when each individual piece of steel is tested to the relevant requirements in EN 1993-1-1:2022 and EN 1090-2:2018+A1:2024.

The main content is organized into:

• modifications throughout the whole document
• changes to the European foreword and Introduction
• Clause 1, Scope
• Clause 3, Terms, definitions and symbols
• Clause 4, Selection of materials to avoid brittle fracture
• Clause 5, Avoidance of lamellar tearing by the specification of through thickness properties
• Annex A, Specific rules for gusset plates with cut-outs in spade details

What are the key requirements of SIST EN 1993-1-10:2025/oprA1:2026?

SIST EN 1993-1-10:2025/oprA1:2026 sets up a practical selection process: choose the steel quality from the fracture toughness demand, the element thickness, the reference temperature and the design situation. In practice, that means the designer must link the grade or Charpy subgrade to the real structural condition, not only to the nominal steel grade.

Selecting steel quality to avoid brittle fracture

Clause 4 keeps the focus on steel quality rather than generic material choice. The selection is based on material toughness, member shape and dimensions, thickness of the loaded element, and the combination of actions in the design situation.

Clause 4.2.2 uses a flowchart and tabulated values to determine the maximum permissible thickness for different applied stress ratios and steel types. That matters because a steel grade that is acceptable for one thickness may not be acceptable for a thicker plate or section under the same temperature and loading.

Clause 4.2.2.3 links those tabulated values to classified constructional details for the nominal stress method. For designers and reviewers, this means detail category, joint type and fabrication context are part of the toughness check, not separate from it.

Clause 4.3 adds toughness quality requirements for specific cases. The amendment keeps these special provisions tied to tensile resistance and seismic design, so projects with those demands need extra attention beyond the basic grade selection.

Clause 4.4 covers welding in cold-formed zones. The amended text keeps the condition-based approach for permitting welding there, including a note for cold-formed hollow sections according to EN 10219.

Avoiding lamellar tearing

Clause 5 addresses lamellar tearing by specifying through-thickness properties for welded elements. The rules focus on strain in the through-thickness direction, because that is the mechanism that can damage rolled steel plates and welded details.

Clause 5.2 uses the Z-value and related checks to decide whether through-thickness properties are needed. In practice, that is the part a purchaser or fabricator uses when a welded joint, shrinkage or restraint could drive tearing.

Special gusset plate rules

Annex A gives specific rules for gusset plates with cut-outs in spade details. It uses geometry, net cross-section width and ratios based on plate dimensions to specify the steel quality and the design check for that special connection type.

What terms does SIST EN 1993-1-10:2025/oprA1:2026 define?

• Brittle fracture - sudden fracture risk that the standard addresses by selecting adequate steel quality and toughness.
• Charpy subgrade - the steel quality level used to classify fracture toughness.
• Lamellar tearing - cracking risk in welded elements caused by through-thickness strain in the steel.
• Through-thickness properties - properties in the thickness direction that are specified to reduce lamellar tearing.
• Parent material - the base steel material before welding or fabrication; the standard applies to this material only.
• Execution Classes (EXC) - execution quality classes used with the material selection rules and thickness tables.
• Upper shelf toughness - toughness condition needed in specific cases for tensile and seismic design.

Who uses SIST EN 1993-1-10:2025/oprA1:2026?

SIST EN 1993-1-10:2025/oprA1:2026 is used by structural engineers, steel designers, detailers, fabricators, inspectors and quality managers working on steel structures. It is also relevant to buyers and specifiers who need to order the correct steel grade, through-thickness quality or execution condition for a project.

The standard is used in buildings, bridges and other steel structures where welded details, thickness effects, cold-formed zones or seismic demands can influence toughness selection. It is especially useful when a project needs clear documentation of steel quality before fabrication or welding starts.

What changed in SIST EN 1993-1-10:2025/oprA1:2026 from the previous edition?

SIST EN 1993-1-10:2025/oprA1:2026 is a draft amendment to EN 1993-1-10:2025. The foreword says the main changes are:

• removal of the restriction on the choice of material for welding in cold-formed zones for steel grades up to S460, based on recent research and publications
• correction of technical and editorial points to improve clarity and user friendliness
• updates throughout the document, including the scope, terms, Clause 4, Clause 5 and Annex A

Which standards are used with SIST EN 1993-1-10:2025/oprA1:2026?

• EN 1990-1 - provides the basis for structural and geotechnical design used with the material selection rules.
• EN 1991 (all parts) - provides actions and design situations used when checking steel quality.
• EN 1993-1-1:2022 - supplies the structural steel grades and testing conditions named in the scope.
• Other relevant parts of EN 1993-1 (all parts) - provide the companion Eurocode 3 design rules needed alongside this part.
• EN 1090-2:2018+A1:2024 - gives execution requirements that the standard assumes for welded steelwork.
• EN 1090-4 - provides execution quality conditions referenced in the assumptions.
• EN 10219 - is referenced for cold-formed hollow sections in the welding provisions.

What does the SIST EN 1993-1-10:2025/oprA1:2026 document contain?

The document contains a selection procedure, a flowchart, tabulated thickness limits, formulas and notes for choosing steel quality against brittle fracture. It also contains rules for through-thickness properties, including tables for lamellar tearing prevention and Z-value related checks.

Annex A contains a separate method for gusset plates with cut-outs in spade details, including a figure, a design formula and several tables for geometry-based selection and verification. These elements are used for design checks, detailing, fabrication decisions and project documentation.

SLOVENSKI STANDARD
01-julij-2026
Evrokod 3: Projektiranje jeklenih konstrukcij - 1-10. del: Izbira kakovosti jekla
glede na žilavost in lamelarni lom
Eurocode 3 - Design of steel structures - Part 1-10: Material toughness and through-
thickness properties
Eurocode 3 - Bemessung und Konstruktion von Stahlbauten - Teil 1-10:
Stahlsortenauswahl im Hinblick auf Bruchzähigkeit und Eigenschaften in Dickenrichtung
Eurocode 3 - Calcul des structures en acier - Partie 1-10 : Ténacité du matériau et
propriétés dans le sens de l'épaisseur
Ta slovenski standard je istoveten z: EN 1993-1-10:2025/prA1
ICS:
91.010.30 Tehnični vidiki Technical aspects
91.080.13 Jeklene konstrukcije Steel structures
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
EUROPEAN STANDARD
EN 1993-1-10:2025
NORME EUROPÉENNE
EUROPÄISCHE NORM
prA1
May 2026
ICS 91.010.30
English Version
Eurocode 3 - Design of steel structures - Part 1-10:
Material toughness and through-thickness properties
Eurocode 3 - Calcul des structures en acier - Partie 1- Eurocode 3 - Bemessung und Konstruktion von
10 : Ténacité du matériau et propriétés dans le sens de Stahlbauten - Teil 1-10: Stahlsortenauswahl im
l'épaisseur Hinblick auf Bruchzähigkeit und Eigenschaften in
Dickenrichtung
This draft amendment is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 250.

This draft amendment A1, if approved, will modify the European Standard EN 1993-1-10:2025. If this draft becomes an
amendment, CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for
inclusion of this amendment into the relevant national standard without any alteration.

This draft amendment was established by CEN in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC
Management Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are
aware and to provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without
notice and shall not be referred to as a European Standard.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 1993-1-10:2025/prA1:2026 E
worldwide for CEN national Members.

Contents Page
1 Modifications throughout the whole document . 4
2 Modifications to the European foreword . 4
3 Modifications to the Introduction . 5
4 Modifications to Clause 1, “Scope” . 6
5 Modifications to Clause 3, “Terms, definitions and symbols” . 6
6 Modifications to Clause 4, “Selection of materials to avoid brittle fracture” . 7
7 Modifications to Clause 5, “Avoidance of lamellar tearing by the specification of through
thickness properties” . 12
8 Modifications to Annex A, “Specific rules for gusset plates with cut-outs in spade details”
............................................................................................................................................................................. 13
European foreword
This document (EN 1993-1-10:2025/prA1:2026) has been prepared by Technical Committee
CEN/TC 250 “Structural Eurocodes”, the secretariat of which is held by BSI. CEN/TC 250 is responsible
for all Structural Eurocodes and has been assigned responsibility for structural and geotechnical design
matters by CEN.
This document is an amendment to EN 1993-1-10:2025 and is currently submitted to the CEN Enquiry.
The following main changes to EN 1993-1-10:2025 are included in the amendment:
— A restriction of the rules for the choice of material in case of welding in cold formed zones for steel
grades up to S460 was skipped, based on recent research works and publications.
— This amendment corrects technical and editorial points in EN 1993-1-10:2025 to increase the clarity
and user friendliness.
The first generation of EN Eurocodes was published between 2002 and 2007. This document forms part
of the second generation of the Eurocodes, which have been prepared under Mandate M/515 issued to
CEN by the European Commission and the European Free Trade Association.
The Eurocodes have been drafted to be used in conjunction with relevant execution, material, product
and test standards, and to identify requirements for execution, materials, products and testing that are
relied upon by the Eurocodes.
The Eurocodes recognize the responsibility of each Member State and have safeguarded their right to
determine values related to regulatory safety matters at national level through the use of National
Annexes.
1 Modifications throughout the whole document
Add “-1:2023+A1:2026” to the reference “EN 1990” in Clause 2 and update throughout the text when a
dated reference is given.
Add part number “-1” to the reference “EN 1990” and update throughout the text when an undated reference
is given.
2 Modifications to the European foreword
First bullet:
• Replace “application” with “scope”.
• Replace “non-standard” with “include”.
Second bullet:
• Add “material” before “selection”.
• Delete “of a design”.
• Replace “introduced” with “included”.
Third bullet:
• Delete “the possibility to consider”.
• Replace “execution classes” with “Execution Classes”.
• Add “(EXC) for the material selection” after “execution classes”.
• Delete “in design” before “procedure”.
• Replace “(4.12, 4.2.2, 4.2.2.2, 4.2.2.3, 4.3)” with “(4.2, 4.3)”.
Fourth bullet:
• Replace “(4.2.1)” with “(4.2)”.
Fifth bullet:
• Replace “(4.2.1)” with “(4.2.2)”.
Sixth bullet:
• Replace “(4.2.2.2)” with “(4.2.3)”.
Seventh bullet:
• Replace “former tabulated values mainly derived for bridge design given in former Table 2.1 are
related to Execution Classes EXC3 and EXC4 and transferred to new Table 4.2 (4.2.2.2)” with “the
maximum permissible values of element thickness given in Table 2.1 of EN 1993-1-10:2005 were
developed for bridge structures; this information has been transferred to Table 4.2 and related to
EXC3 and EXC4;”.
Eighth bullet:
• Replace “new tabulated values have been introduced related” with “the maximum permissible values
of element thickness”.
• Replace “see” with “are given in”.
Ninth bullet:
• Replace “new design rules for” with “construction”.
• Add “those given in” before “EN 1993-1-9”.
• Replace “have been” with “are”.
Eleventh bullet:
• Replace “material related” with “the”.
• Replace “shifted” with “transferred”.
• Delete “subclause” before “4.4”.
Twelfth bullet:
• Replace “dealing with” with “addressing”.
3 Modifications to the Introduction
0.1 Replace “— New parts are under development, e.g. Eurocode for design of structural glass”
with “— EN 19100 Eurocode 10 — Design of glass structures”.
0.1 Add the following new list item: “— New parts are under development, e.g. Eurocode for design of
fibre-polymer composite structures and for design of tensioned membrane structures”.
0.2 Replace in the first paragraph the reference to EN 1990 with “EN 1990-1 — Basis of structural and
geotechnical design — Part 1: New structures”.
0.2 Replace the list of the various parts of EN 1993 with:
“EN 1993-1-1, Eurocode 3 — Design of Steel Structures — Part 1-1: General rules and rules for buildings;
EN 1993-1-2, Eurocode 3 — Design of Steel Structures — Part 1-2: Structural fire design;
EN 1993-1-3, Eurocode 3 — Design of Steel Structures — Part 1-3: Cold-formed members and sheeting;
NOTE Cold-formed hollow sections supplied according to EN 10219 (all parts) are covered in EN 1993-1-1.
EN 1993-1-4, Eurocode 3 — Design of Steel Structures — Part 1-4: Stainless steel structures;
EN 1993-1-5, Eurocode 3 — Design of Steel Structures — Part 1-5: Plated structural elements;
EN 1993-1-6, Eurocode 3 — Design of Steel Structures — Part 1-6: Strength and stability of shell structures;
EN 1993-1-7, Eurocode 3 — Design of Steel Structures — Part 1-7: Plate assemblies with elements under
transverse loads;
EN 1993-1-8, Eurocode 3 — Design of Steel Structures — Part 1-8: Joints;
EN 1993-1-9, Eurocode 3 — Design of Steel Structures — Part 1-9: Fatigue;
EN 1993-1-10, Eurocode 3 — Design of Steel Structures — Part 1-10: Material toughness and through-
thickness properties;
EN 1993-1-11, Eurocode 3 — Design of Steel Structures — Part 1-11: Tension components;
EN 1993-1-12, Eurocode 3 — Design of Steel Structures — Part 1-12: Additional rules for steel grades up to
S960;
EN 1993-1-13, Eurocode 3 — Design of Steel Structures — Part 1-13: Beams with large web openings;
EN 1993-1-14, Eurocode 3 — Design of Steel Structures — Part 1-14: Design assisted by finite element
analysis;
EN 1993-2, Eurocode 3 — Design of Steel Structures — Part 2: Bridges;
EN 1993-3, Eurocode 3 — Design of Steel Structures — Part 3: Towers, masts and chimneys;
EN 1993-4-1, Eurocode 3 — Design of Steel Structures — Part 4-1: Silos;
EN 1993-4-2, Eurocode 3 — Design of Steel Structures — Part 4-2: Tanks;
EN 1993-5, Eurocode 3 — Design of Steel Structures — Part 5: Piling;
EN 1993-6, Eurocode 3 — Design of Steel Structures — Part 6: Crane supporting structures;
EN 1993-7, Eurocode 3 — Design of Steel Structures — Part 7: Sandwich panels (under preparation).”.
0.3 Delete “general design”.
0.3 Add “(i)” after “rules for”.
0.3 Replace “to avoid” with “(ii) prevention of”.
0.3 Add “in welded elements” after “lamellar tearing”.
0.5 Add “notes to” between “through” and “the following clauses” in 0.5.
4 Modifications to Clause 1, “Scope”
1.1(2) Replace “specifies” with “provides”.
1.1(2) Add “for all steel grades from S235 up to and including S700” after “lamellar tearing”.
1.1(5) Replace “specifies” with “gives”.
1.1(6) Replace “EN 1993-1-10 specifies rules that” with “The provisions in this document”.
1.1(6) Add “s” to steel after “applies to”.
1.1(6) Replace “materials” with “complying with the requirements of”.
1.1(6) Replace “covered by” with “5.1(3) of”.
1.1(6) Delete “5.1 (3)” after “EN 1993-1-1:2022,”.
1.1(6) Replace “the requirements” with “5.2.1”.
1.1(6) Replace “5.2.1 and” with “or 5.1 of”.
1.1(6) Delete “, 5.1” after “EN 1090-2:2018”.
5 Modifications to Clause 3, “Terms, definitions and symbols”
3.1.2 Delete “showing the relationship KV(T)” and replace “in which” with “where”.
3.1.3 Replace “in which” with “where” and swap the whole content of 3.1.3 with 3.1.2.
3.1.4, Figure 3.1, NOTE 1, Add “The” before “Charpy” and replace “an explanation” with “the definition”.
3.1.5 Replace “at which” with “where”.
3.1.8 Replace “modified” with “adjusted”, add “,” after “strain rates” and add ”,” after “cold forming”.
3.1.9 Delete “pr” before “EN 1991-1-5”.
3.1.10 Replace “bound” with “chemically bonded”.
3.2
• For ∆T replace “shift” with “adjustment”,

ε
• For ∆T replace “shift” with “adjustment”,
ε, cf
• For ΔT replace “shift” with “adjustment”.
σ
6 Modifications to Clause 4, “Selection of materials to avoid brittle fracture”
4 Replace in the title of Clause 4 “materials” with “steel quality”.
4.1(1) Replace in the first line “materials” with
...