Aerospace series - Nut, anchor, self-locking, fixed, 90° corner, reduced series, with counterbore, in heat resisting steel, MoS2 lubricated - Classification: 1 100 MPa (at ambient temperature) / 315 °C

This document specifies the characteristics of 90° corner, reduced series, counterbored fixed anchor nuts, with a self-locking feature achieved by forming the upper portion out-of-round, in heat resisting steel, MoS2 lubricated.
Classification: 1 100 MPa  / 315 °C .

Luft- und Raumfahrt - Annietmutter, selbstsichernd, einseitiger verkürzter 90° Eckflansch, mit zylindrischer Aussenkung, aus hochwarmfestem Stahl, MoS2-geschmiert - Klasse: 1 100 MPa (bei Raumtemperatur) / 315 °C

Série aérospatiale - Écrous à river, à freinage interne, fixes, d'angle 90°, série réduite, avec chambrage, en acier résistant à chaud, lubrifiés MoS2 - Classification : 1 100 MPa (à température ambiante) / 315 °C

Le présent document spécifie les caractéristiques des écrous à river fixes, d’angle 90°, série réduite, avec chambrage, à freinage interne obtenu par déformation de la partie supérieure, en acier résistant à chaud, lubrifiés au MoS2.
Classification : 1 100 MPa /315 °C.

Aeronavtika - Matica, sidrišče, samozapiralne, fiksne, rob 90°, skrajšana serija, z izvrtino za vijake, iz toplotnoodpornega jekla, namazane z MoS2 - Klasifikacija: 1 100 MPa (pri temperaturi okolice)/315 °C

General Information

Status
Not Published
Public Enquiry End Date
22-Oct-2024
ICS
49.030.30 - Nuts
Technical Committee
I13 - Imaginarni 13
Current Stage
5020 - Formal vote (FV) (Adopted Project)
Start Date
18-Nov-2025
Due Date
06-Jan-2026
Completion Date
19-Nov-2025
Ref Project
FprEN 3750 - Aerospace series - Nut, anchor, self-locking, fixed, 90° corner, reduced series, with counterbore, in heat resisting steel, MoS2 lubricated - Classification: 1 100 MPa (at ambient temperature) / 315 °C

Relations

Revises
SIST EN 3750:2010 - Aerospace series - Nuts, anchor, self-locking, fixed, 90° corner, reduced series, with counterbore, in heat resisting steel, MoS2 lubricated - Classification: 1100 MPa (at ambient temperature)/315 °C
Effective Date
06-Dec-2023

Overview

The prEN 3750:2024 standard, developed by CEN under the Aerospace and Defence Industries Association of Europe (ASD-STAN), specifies requirements for a specialized aerospace fastener: the self-locking, fixed, 90° corner anchor nut. This nut belongs to a reduced series with a counterbored design, made from heat-resisting steel and lubricated with molybdenum disulfide (MoS2). It is engineered to withstand high mechanical stresses at elevated temperatures, specifically a classification of 1,100 MPa tensile strength at ambient temperature and safe operation up to 315 °C.

This standard revises and supersedes EN 3750:2010 by incorporating updated normative references, precision corrections in dimensional drawings, and improved documentation, making it essential for aerospace components demanding reliable performance under heat and mechanical load.

Key Topics

  • Nut Configuration and Dimensions
    The document details the nut’s configuration, including exact dimensions, mass, and tight tolerances, all conforming to ISO 9156 and ISO 8788 standards. The design includes a distinctive 90° corner and an out-of-round upper portion that achieves the self-locking function critical for vibration resistance.

  • Materials and Heat Resistance
    Nuts shall be manufactured from heat-resisting steel grades as specified in EN 2398, EN 2399, EN 3638, and EN 3639 standards. Heat treatment ensures the nut reaches the required 1,100 MPa tensile strength while maintaining stability at temperatures up to 315 °C.

  • Surface Treatment and Lubrication
    The nuts undergo passivation according to EN 2516 and feature MoS2 lubrication compliant with EN 2491 for enhanced high-temperature performance and corrosion resistance.

  • Designation and Marking
    Nuts are designated by their thread diameter code (e.g., 060 corresponds to MJ6 × 1 thread), with marking following EN 2424:2008 guidelines to ensure traceability and quality verification.

  • Manufacturer and Quality Assurance Requirements
    Manufacturers must be approved aerospace production organizations implementing rigorous quality management systems like EN 9100. Products must undergo thorough qualification aligned with EN 9133 standards or equivalent processes.

Applications

The prEN 3750:2024 standard is crucial for aerospace manufacturing sectors that require:

  • High-reliability fastening solutions in aerospace structures
    Ideal for aerospace assemblies where nuts must maintain secure locking under thermal cycling and mechanical vibration.

  • Heat-resistant fastening components in engines and control systems
    The MoS2 lubrication and heat-resistant steel allow these nuts to function efficiently at elevated temperatures up to 315 °C without degradation.

  • Lightweight yet durable fastening elements for aircraft and spacecraft
    The reduced series design addresses space and weight constraints while ensuring robust mechanical properties.

  • Standardized components for aerospace supply chains
    Adoption of this standard ensures interchangeability and quality assurance in manufacturing and maintenance.

Related Standards

  • EN 2398 & EN 2399 – Heat resisting steel bars for bolts used in high-temperature aerospace applications
  • EN 2491 – Specifications for molybdenum disulfide dry lubricants coating methods
  • ISO 5855-2 & ISO 5858 – Thread dimensions and procurement specifications for aerospace nuts and bolts
  • EN 9100 – Quality management systems for aviation, space, and defense organizations
  • EN 9133 – Qualification procedures for aerospace standard products
  • ISO 8788 – Tolerances of form and position for aerospace nuts

By adhering to prEN 3750:2024, aerospace manufacturers and suppliers ensure that their fastening solutions meet stringent requirements for strength, thermal resistance, and locking reliability - critical attributes for aerospace safety and performance.

Keywords: Aerospace nuts standard, self-locking anchor nuts, heat resisting steel nut, molybdenum disulfide lubrication, aerospace fasteners, fixed 90° corner nut, aerospace quality management, high temperature nuts aerospace, reduced series counterbored nut.

Frequently Asked Questions

kSIST FprEN 3750:2025 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Aerospace series - Nut, anchor, self-locking, fixed, 90° corner, reduced series, with counterbore, in heat resisting steel, MoS2 lubricated - Classification: 1 100 MPa (at ambient temperature) / 315 °C". This standard covers: This document specifies the characteristics of 90° corner, reduced series, counterbored fixed anchor nuts, with a self-locking feature achieved by forming the upper portion out-of-round, in heat resisting steel, MoS2 lubricated. Classification: 1 100 MPa / 315 °C .

This document specifies the characteristics of 90° corner, reduced series, counterbored fixed anchor nuts, with a self-locking feature achieved by forming the upper portion out-of-round, in heat resisting steel, MoS2 lubricated. Classification: 1 100 MPa / 315 °C .

kSIST FprEN 3750:2025 is classified under the following ICS (International Classification for Standards) categories: 49.030.30 - Nuts. The ICS classification helps identify the subject area and facilitates finding related standards.

kSIST FprEN 3750:2025 has the following relationships with other standards: It is inter standard links to SIST EN 3750:2010. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.

kSIST FprEN 3750:2025 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
oSIST prEN 3750:2024
01-oktober-2024
Aeronavtika - Matica, sidrišče, samozapiralne, fiksne, rob 90°, skrajšana serija, z
izvrtino za vijake, iz toplotnoodpornega jekla, namazane z MoS2 - Klasifikacija: 1
110 MPa (pri temperaturi okolice)/315 °C
Aerospace series - Nut, anchor, self-locking, fixed, 90° corner, reduced series, with
counterbore, in heat resisting steel, MoS2 lubricated - Classification: 1 100 MPa (at
ambient temperature) / 315 °C
Luft- und Raumfahrt - Annietmutter, selbstsichernd, einseitiger verkürzter 90°
Eckflansch, mit zylindrischer Aussenkung, aus hochwarmfestem Stahl, MoS2-geschmiert
- Klasse: 1 100 MPa (bei Raumtemperatur) / 315 °C
Série aérospatiale - Écrous à river, à freinage interne, fixes, d'angle 90°, série réduite,
avec chambrage, en acier résistant à chaud, lubrifiés MoS2 - Classification : 1 100 MPa
(à température ambiante) / 315 °C
Ta slovenski standard je istoveten z: prEN 3750
ICS:
49.030.30 Matice Nuts
oSIST prEN 3750:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN 3750:2024
oSIST prEN 3750:2024
DRAFT
EUROPEAN STANDARD
prEN 3750
NORME EUROPÉENNE
EUROPÄISCHE NORM
August 2024
ICS 49.030.30 Will supersede EN 3750:2010
English Version
Aerospace series - Nut, anchor, self-locking, fixed, 90°
corner, reduced series, with counterbore, in heat resisting
steel, MoS2 lubricated - Classification: 1 100 MPa (at
ambient temperature) / 315 °C
Série aérospatiale - Écrous à river, à freinage interne, Luft- und Raumfahrt - Annietmutter, selbstsichernd,
fixes, d'angle 90°, série réduite, avec chambrage, en einseitiger verkürzter 90° Eckflansch, mit zylindrischer
acier résistant à chaud, lubrifiés MoS2 - Classification : Aussenkung, aus hochwarmfestem Stahl, MoS2-
1 100 MPa (à température ambiante) / 315 °C geschmiert - Klasse: 1 100 MPa (bei Raumtemperatur)
/ 315 °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
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 3750:2024 E
worldwide for CEN national Members.

oSIST prEN 3750:2024
prEN 3750:2024 (E)
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 — Masses . 5
4.2 Materials . 5
4.3 Surface treatment . 5
5 Designation . 6
6 Marking . 7
7 Technical specification . 7
7.1 General. 7
7.2 Approval of manufacturers . 7
7.3 Qualification of product . 7
Bibliography . 8

oSIST prEN 3750:2024
prEN 3750:2024 (E)
European foreword
This document (prEN 3750:2024) has been prepared by the Aerospace and Defence Industries
Association of Europe — Standardization (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 Servi
...

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