SIST EN 3531:2025

Aerospace series - Steel X2NiCoMo18 8 5 (1.6359) - Vacuum induction melted and vacuum arc remelted - Solution treated and precipitation treated - Sheets and strips - a ≤ 6 mm - 1 750 MPa ≤ Rm ≤ 2 000 MPa

This document specifies the requirements relating to:
Steel X2NiCoMo18-8-5 (1.6359)
Vacuum induction melted and vacuum arc remelted
Solution treated and precipitation treated
Sheets and strips
a ≤ 6 mm
1 750 MPa ≤ Rm ≤ 2 000 MPa
for aerospace applications.
W.nr: 1.6359
ASD-STAN designation: FE-PM2701

Luft- und Raumfahrt - Stahl X2NiCoMo18 8 5 (1.6359) - Vakuuminduktionserschmolzen und mit selbstverzehrender Elektrode im Vakuum umgeschmolzen - Lösungsgeglüht und ausgelagert - Bleche und Bänder - a ≤ 6 mm - 1 750 MPa ≤ Rm ≤ 2 000 MPa

Dieses Dokument legt die Anforderungen an:
Stahl X2NiCoMo18 8 5 (1.6359)
Vakuuminduktionserschmolzen und vakuumlichtbogenumgeschmolzen
Lösungsgeglüht und ausscheidungsgehärtet
Bleche und Bänder
a ≤ 6 mm
1 750 MPa ≤ Rm ≤ 2 000 MPa
für Anwendungen in der Luft- und Raumfahrt fest.
Werkstoffnummer: 1.6359
ASD-STAN-Bezeichnung: FE-PM2701

Série aérospatiale - Acier X2NiCoMo18 8 5 (1.6359) - Élaboré sous vide et refondu par arc sous vide - Mis en solution et vieilli - Tôles et bandes - a ≤ 6 mm - 1 750 MPa ≤ Rm ≤ 2 000 MPa

Le présent document spécifie les exigences relatives à :
Acier X2NiCoMo18-8-5 (1.6359)
Élaboré sous vide par induction et refondu sous vide par arc
Mis en solution et précipité
Tôles et bandes
a ≤ 6 mm
1 750 MPa ≤ Rm ≤ 2 000 MPa
pour les applications aérospatiales.
Désignation ASD-STAN : FE-PM2701
Numéro de matériau : 1.6359

Aeronavtika - Jeklo X2NiCoMo18-8-5 (1.6359) - Indukcijsko vakuumsko taljeno in obločno vakuumsko pretaljeno - Topilno žarjeno in utrjeno z obločenjem - Pločevina in trakovi - a ≤ 6 mm - 1 750 MPa ≤ Rm ≤ 2 000 MPa

Ta dokument določa zahteve, ki se navezujejo na: jeklo X2NiCoMo18-8-5 (1.6359), indukcijsko vakuumsko taljeno in obločno vakuumsko pretaljeno, topilno žarjeno in utrjeno z obločenjem, pločevino in trakove, a ≤ 6 mm, 1750 MPa ≤ Rm ≤ 2000 MPa za uporabo v aeronavtiki. Št. W.: 1.6359. Oznaka ASD-STAN: FE-PM2701.

General Information

• Status: Published
• Public Enquiry End Date: 11-Sep-2024
• Publication Date: 23-Sep-2025
• ICS: 49.025.10 - Steels
• ICS: 77.140.50 - Flat steel products and semi-products
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-Sep-2025
• Due Date: 23-Nov-2025
• Completion Date: 24-Sep-2025
• Ref Project: EN 3531:2025 - Aerospace series - Steel X2NiCoMo18-8-5 (1.6359) - Vacuum induction melted and vacuum arc remelted - Solution treated and precipitation treated - Sheets and strips - a ≤ 6 mm - 1 750 MPa ≤ Rm ≤ 2 000 MPa

Relations

• Refers: SIST EN 2043:2014 - Aerospace series - Metallic materials - General requirements for semi-finished product qualification (excluding forgings and castings)
• Effective Date: 28-Jan-2026
• Refers: SIST EN 4700-001:2025 - Aerospace series - Steel and heat-resisting alloys - Wrought products - Technical specification - Part 001: Plates, sheets and strips
• Effective Date: 28-Jan-2026
• Refers: SIST EN 2951:2019 - Aerospace series - Metallic materials - Micrographic determination of content of non-metallic inclusions
• Effective Date: 28-Jan-2026
• Referred By: SIST EN 4632-004:2014 - Aerospace series - Weldability and brazeability of materials in aerospace constructions - Part 004: Welding and brazing of homogeneous assemblies of high alloyed steels
• Effective Date: 28-Jan-2026
• Revises: SIST EN 3531:2009 - Aerospace series - Steel FE-PM2701 (X2NiCoMo18-8-5) - Vacuum induction melted and vacuum arc remelted - Solution treated and precipitation treated - Sheet and strip - a ≤ 6 mm - 1 750 MPa ≤ Rm ≤ 2 000 MPa
• Effective Date: 19-Jun-2024
• Revises: SIST EN 3431:2008 - Aerospace series - Nuts, hexagonal, self-locking, with counterbore and captive washer, in heat resisting steel, silver plated - Classification: 1 100 MPa (at ambient temperature) / 425 °C
• Effective Date: 22-May-2024

Overview

SIST EN 3531:2025 is a European standard developed by CEN for aerospace applications. It specifies technical requirements for steel X2NiCoMo18-8-5 (material number 1.6359), supplied as vacuum induction melted and vacuum arc remelted (VIM+VAR) sheets and strips, with thicknesses up to 6 mm. The material is solution treated and precipitation treated, yielding a tensile strength in the range of 1,750 MPa to 2,000 MPa, making it suitable for demanding aerospace components requiring high strength and reliability.

Keywords: aerospace steel, SIST EN 3531:2025, X2NiCoMo18-8-5, high-strength sheet, vacuum arc remelted, vacuum induction melted, 1.6359, aerospace standard, steel strip, solution treated, precipitation treated.

Key Topics

• Material Specification:
  SIST EN 3531:2025 defines requirements specific to X2NiCoMo18-8-5 steel, also known by its Werkstoffnummer (W.nr) 1.6359 and ASD-STAN FE-PM2701 designation.

• Production Process:

  • Vacuum induction melting and vacuum arc remelting methods
  • Solution treatment and subsequent precipitation treatment for mechanical property optimization

• Product Forms and Dimensions:

  • Applies to sheets and strips with a thickness (a) not exceeding 6 mm
  • Rolled product forms for semi-finished and finished aerospace parts

• Mechanical Properties:

  • Tensile strength (Rm) between 1,750 MPa and 2,000 MPa
  • Proof stress (Rp0.2) at or above 1,650 MPa
  • Specific requirements for elongation and hardness

• Testing and Acceptance:

  • Grain size, inclusion content, and external surface quality are covered
  • Inclusion assessment through referenced standards
  • Detailed marking and inspection requirements

• Standardized Delivery Condition:

  • Supplied in the solution-treated or solution and precipitation-treated condition, ensuring consistent mechanical performance

Applications

SIST EN 3531:2025 is primarily intended for use in aerospace engineering, where lightweight and high-strength materials are critical. Common applications include:

• Structural airframe components exposed to high mechanical loads
• Engine and propulsion system parts requiring superior tensile properties
• Fasteners, brackets, and mounting hardware where consistent quality and traceability are demanded
• Precision strips and sheet elements in detailed assemblies of aircraft, satellites, and space vehicles

The defined strength range and stringent production controls make X2NiCoMo18-8-5 a preferred material for highly reliable components that must meet rigorous safety and endurance requirements.

Related Standards

SIST EN 3531:2025 references and aligns with several related European aerospace standards:

• EN 2043: Aerospace series - General requirements for semi-finished product qualification
  Covers qualification principles for products, excluding forgings and castings.

• EN 2951: Aerospace series - Micrographic determination of non-metallic inclusions
  Details assessment procedures for evaluating steel cleanliness, which influences performance.

• EN 4700-001: Aerospace series - Steel and heat resisting alloys - Technical specification for plate, sheet, and strip
  Provides general technical specifications applicable to steel flat products in aerospace.

• EN 4258 & EN 4500-005:
  Set the organizational framework and drafting rules for aerospace metallic material standards.

These supporting standards ensure that SIST EN 3531:2025 is part of an integrated system, allowing manufacturers and users to achieve continual quality and performance in aerospace steel applications.

Practical Value

Implementing SIST EN 3531:2025 enables aerospace manufacturers to select high-strength steel products with verified consistency and traceability. By adhering to internationally harmonized requirements, suppliers can ensure product compatibility throughout the aerospace supply chain, promoting safer and more efficient structures for both civil and military aviation projects.

Standards Content (Sample)

SLOVENSKI STANDARD
01-november-2025
Aeronavtika - Jeklo X2NiCoMo18-8-5 (1.6359) - Indukcijsko vakuumsko taljeno in
obločno vakuumsko pretaljeno - Topilno žarjeno in utrjeno z obločenjem -
Pločevina in trakovi - a ≤ 6 mm - 1 750 MPa ≤ Rm ≤ 2 000 MPa
Aerospace series - Steel X2NiCoMo18 8 5 (1.6359) - Vacuum induction melted and
vacuum arc remelted - Solution treated and precipitation treated - Sheets and strips - a ≤
6 mm - 1 750 MPa ≤ Rm ≤ 2 000 MPa
Luft- und Raumfahrt - Stahl X2NiCoMo18 8 5 (1.6359) - Vakuuminduktionserschmolzen
und mit selbstverzehrender Elektrode im Vakuum umgeschmolzen - Lösungsgeglüht und
ausgelagert - Bleche und Bänder - a ≤ 6 mm - 1 750 MPa ≤ Rm ≤ 2 000 MPa
Série aérospatiale - Acier X2NiCoMo18 8 5 (1.6359) - Élaboré sous vide et refondu par
arc sous vide - Mis en solution et vieilli - Tôles et bandes - a ≤ 6 mm - 1 750 MPa ≤ Rm ≤
2 000 MPa
Ta slovenski standard je istoveten z: EN 3531:2025
ICS:
49.025.10 Jekla Steels
77.140.50 Ploščati jekleni izdelki in Flat steel products and semi-
polizdelki products
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 3531
EUROPEAN STANDARD
NORME EUROPÉENNE
September 2025
EUROPÄISCHE NORM
ICS 49.025.10 Supersedes EN 3531:2007
English Version
Aerospace series - Steel X2NiCoMo18-8-5 (1.6359) -
Vacuum induction melted and vacuum arc remelted -
Solution treated and precipitation treated - Sheets and
strips - a  6 mm - 1 750 MPa  Rm  2 000 MPa
Série aérospatiale - Acier X2NiCoMo18 8 5 (1.6359) - Luft- und Raumfahrt - Stahl X2NiCoMo18-8-5 (1.6359)
Élaboré sous vide par induction et refondu sous vide - Vakuuminduktionserschmolzen und
par arc - Mis en solution et précipité - Tôles et bandes - vakuumlichtbogenumgeschmolzen - Lösungsgeglüht
a  6 mm - 1 750 MPa  Rm  2 000 MPa und ausscheidungsgehärtet - Bleche und Bänder - a  6
mm - 1 750 MPa  Rm  2 000 MPa
This European Standard was approved by CEN on 27 July 2025.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists 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.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3531:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Introduction . 4
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Requirements . 5
Bibliography . 9

European foreword
This document (EN 3531:2025) has been prepared by ASD-STAN.
After enquiries and votes carried out in accordance with the rules of this Association, this document has
received the approval of the National Associations and the Official Services of the member countries of
ASD-STAN, prior to its presentation to CEN.
This document shall be given the status of a national standard, either by publication of an identical text
or by endorsement, at the latest by March 2026, and conflicting national standards shall be withdrawn
at the latest by March 2026.
Attention is drawn to the possibility that some o
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