oSIST prEN 3377:2026
(Main)Aerospace series - Nuts, hexagonal, self-locking, in heat resisting steel FE-PA92HT (A286) - Classification : 1 100 MPa (at ambient temperature) / 425 °C
General Information
- Abstract
- Status
- Not Published
- Public Enquiry End Date
- 09-Jul-2026
- Technical Committee
- I13 - Imaginarni 13
- Current Stage
- 4020 - Public enquire (PE) (Adopted Project)
- Start Date
- 21-May-2026
- Due Date
- 08-Oct-2026
- Completion Date
- 10-Jul-2026
Overview
oSIST prEN 3377:2026 is a draft European Standard developed by CEN, focused on self-locking hexagonal nuts made from heat resisting steel FE-PA92HT (A286) for aerospace applications. These nuts are classified for performance at a tensile strength of 1 100 MPa at ambient temperature and operational capability up to 425 °C. The standard is designed to supersede EN 3377:1996, ensuring compliance with the latest technical requirements and industry best practices for high-performance aerospace fasteners.
This document provides key characteristics, material specifications, dimensional requirements, technical qualifications, and marking instructions tailored for the aerospace sector, where safety, reliability, and performance under extreme conditions are critical.
Keywords: oSIST prEN 3377:2026, aerospace fasteners, hexagonal nuts, self-locking nuts, FE-PA92HT, A286, 1100 MPa, 425°C, heat resisting steel, CEN, aerospace standard.
Key Topics
Scope and Classification
- Specifies requirements for self-locking, hexagonal nuts in FE-PA92HT (A286) steel.
- Classification: 1 100 MPa tensile strength at ambient temperature, operating temperature up to 425 °C.
Material Requirements
- Heat resisting steel FE-PA92HT (A286) in compliance with EN, TR, and SAE standards.
- Materials can also be referenced from standards such as EN 2399, EN 3638, EN 3639, TR 3791, or SAE AMS5525 for certain thread sizes (MJ3, MJ4).
Configuration and Tolerances
- Defined dimensions, tolerances, and mass according to ISO 7995 and ISO 5855-2 for MJ thread types.
- Outlines engineering features for self-locking function and compatibility with standard aerospace tooling.
Marking and Designation
- Marking in compliance with EN 2424 to ensure traceability.
- Logical designation system for product identification.
Technical Specification and Quality Assurance
- Requires compliance with EN 3152 for technical specifications.
- Manufacturers must have a recognized quality management system (EN 9100 or equivalent).
- Qualification of products in accordance with EN 9133 or agreed procedures.
Applications
Self-locking hexagonal nuts conforming to oSIST prEN 3377:2026 are engineered for aerospace and aviation environments where high strength and resistance to elevated temperatures are essential. Common applications include:
- Aircraft structural assemblies
- Aircraft engine mounting
- Components subject to vibration, where self-locking features prevent loosening
- Any aerospace project requiring high-performance, heat resistant fasteners
By specifying FE-PA92HT (A286) and high strength ratings, this standard ensures suitability for demanding aerospace projects that experience extreme thermal and mechanical stresses.
Related Standards
Several international and European standards are directly referenced or related to oSIST prEN 3377:2026, providing compatibility and alignment within the aerospace fastener ecosystem:
- EN 2399: Heat resisting steel for aerospace bolts
- EN 2424: Marking requirements for aerospace products
- EN 3152: Technical specification for self-locking nuts in heat resisting steel
- EN 3638, EN 3639: Materials specifications for heat-resisting alloys in sheets, plates, wires, and fasteners
- ISO 5855-2: Limit dimensions for MJ threads in bolts and nuts
- ISO 7995: Dimensions for self-locking, hexagonal nuts with MJ threads
- TR 3791: Materials for self-locking aerospace fasteners
- SAE AMS5525: US standard for corrosion and heat-resistant steel
- EN 9100: Quality management systems for aviation, space, and defense
- EN 9133: Qualification procedures for aerospace standard products
Practical Value
By following oSIST prEN 3377:2026, manufacturers and aerospace professionals ensure the delivery of reliable, high-performance, and safety-compliant fastening solutions for advanced aerospace systems. The adoption of recognized material, dimensional, and quality assurance requirements helps promote safety, reduce maintenance, and maintain international compatibility across aerospace supply chains.
Relations
- Effective Date
- 20-Jan-2026
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Frequently Asked Questions
oSIST prEN 3377:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Aerospace series - Nuts, hexagonal, self-locking, in heat resisting steel FE-PA92HT (A286) - Classification : 1 100 MPa (at ambient temperature) / 425 °C". This standard covers: Le présent document spécifie les caractéristiques des écrous hexagonaux, auto-freinés, en FE-PA92HT, pour les applications aérospatiales. Classification : 1 100 MPa /425 °C.
Le présent document spécifie les caractéristiques des écrous hexagonaux, auto-freinés, en FE-PA92HT, pour les applications aérospatiales. Classification : 1 100 MPa /425 °C.
oSIST prEN 3377:2026 is classified under the following ICS (International Classification for Standards) categories: 49.025.10 - Steels; 49.030.30 - Nuts. The ICS classification helps identify the subject area and facilitates finding related standards.
oSIST prEN 3377:2026 has the following relationships with other standards: It is inter standard links to SIST EN 3377:2001. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
oSIST prEN 3377:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2026
Aeronavtika - Matice, šestrobe, samozapiralne, iz toplotnoodpornega jekla FE-
PA92HT (A286) - Klasifikacija: 1100 MPa (pri temperaturi okolice)/425 °C
Aerospace series - Nuts, hexagonal, self-locking, in heat resisting steel FE-PA92HT
(A286) - Classification : 1 100 MPa (at ambient temperature) / 425 °C
Luft- und Raumfahrt - Sechskantmutter, selbstsichernd, aus hochwarmfesten Stahl FE-
PA92HT (A286) - Klasse: 1 100 MPa (bei Raumtemperatur)/425 °C
Ta slovenski standard je istoveten z: prEN 3377
ICS:
49.025.10 Jekla Steels
49.030.30 Matice Nuts
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
EUROPEAN STANDARD
NORME EUROPÉENNE
EUROPÄISCHE NORM
April 2026
ICS 49.030.30 Will supersede EN 3377:1996
English Version
Aerospace series - Nuts, hexagonal, self-locking, in heat
resisting steel FE-PA92HT (A286) - Classification : 1 100
MPa (at ambient temperature) / 425 °C
Luft- und Raumfahrt ¿ Sechskantmutter,
selbstsichernd, aus hochwarmfesten Stahl FE-PA92HT
(A286) ¿ Klasse: 1 100 MPa (bei
Raumtemperatur)/425 °C
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee ASD-
STAN.
If this draft becomes a European Standard, 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.
This draft European Standard 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. prEN 3377:2026 E
worldwide for CEN national Members.
Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Required characteristics . 5
4.1 Configuration – Dimensions – Tolerances – Mass . 5
4.2 Materials . 5
5 Designation . 8
6 Marking . 8
7 Technical specification . 8
7.1 General. 8
7.2 Approval of manufacturers . 8
7.3 Qualification of products . 8
Bibliography . 9
European foreword
This document (prEN 3377:2026) 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 is currently submitted to the CEN Enquiry.
This document will supersede EN 3377:1996.
— Clause 3, “Terms and definitions”, added;
— 4.2, “Materials”, standards TR 3791 and SAE AMS5525 added;
— Clause 7, “Technical specification”, editorially revised.
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