EN 3768:2012

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

This European Standard specifies the characteristics of one lug, 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: 1100 MPa )/315 °C

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

Diese Europäische Norm legt die Merkmale von Annietmuttern mit zylindrischer Aussenkung und einseitigem verkürztem Flansch fest, selbstsichernd durch ovale Formgebung des oberen Teils, aus hochwarmfestem Stahl, MoS2-geschmiert.
Klasse: 1 100 MPa /315 °C

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

Aeronavtika - Zakovne matice, samovarovalne, enostranske, iz jekla, kadmirane, mazane z MoS2 - Klasifikacija: 1100 MPa (pri temperaturi okolice)/315 °C

Ta evropski standard določa značilnosti enostranskih fiksnih zakovnih matic iz skrajšane serije z izvrtino za valjaste vijake in samovarovalno funkcijo, ki jo zagotavlja ovalna oblika zgornjega dela, iz toplotnoodpornega jekla, mazane z MoS2. Razvrstitev: 1 100 MPa1)/315 °C2).

General Information

• Status: Published
• Publication Date: 06-Mar-2012
• Withdrawal Date: 29-Sep-2012
• ICS: 49.030.30 - Nuts
• Technical Committee: ASD-STAN - Aerospace
• Drafting Committee: ASD-STAN/D 3 - Mechanical
• Current Stage: 9093 - Decision to confirm - Review Enquiry
• Start Date: 30-Jun-2017
• Completion Date: 14-Apr-2025
• Ref Project: SIST EN 3768:2012 - Aerospace series - Nuts, anchor, self-locking, one lug, fixed, reduced series, with counterbore, in heat resisting steel, MoS2 lubricated - Classification: 1 100 MPa (at ambient temperature)/315 °C

Overview

EN 3768:2012 specifies the characteristics of aerospace anchor nuts: one-lug, reduced-series, counterbored fixed anchor nuts with a self-locking feature. These nuts are manufactured in heat-resisting steel and supplied MoS2 (molybdenum disulphide) lubricated. The standard classifies the product as 1100 MPa (at ambient temperature) / 315 °C, defining material, marking, designation and performance expectations for use in aviation and space applications.

Key Topics

• Configuration & dimensions: Dimensions and tolerances are referenced to ISO 3191; form and position tolerances follow ISO 8788. The nuts are counterbored and of reduced series with one lug (single-lug) design.
• Self-locking method: Locking is achieved by forming the upper portion out-of-round, providing a mechanical locking feature compatible with aerospace fastener requirements.
• Materials: Heat-resisting steels are specified by referenced EN material standards (EN 2398, EN 2399, EN 3638, EN 3639) or TR 3791 where applicable.
• Surface treatment & lubrication: Surface methods are covered by EN 2491; MoS2 dry lubrication is applied per the standard to ensure consistent friction and high-temperature compatibility.
• Designation & marking: Product designation follows the format described in EN 3768 (e.g., Nut EN3768–060) and marking is specified in EN 2424 (style N).
• Quality & approval: Manufacturer approval and quality systems are aligned with EN 9100; product qualification is referenced to EN 9133.

Applications

EN 3768:2012 nuts are intended for aerospace structural and secondary fastening applications where:

• High mechanical strength (1100 MPa class) is required at ambient conditions.
• Elevated temperature endurance up to 315 °C is necessary without permanent alteration of properties.
• Reliable self-locking is needed to resist vibration and maintain clamp in service.

Typical uses include anchor points in airframe assemblies, high-temperature engine surroundings, and other critical joints where standardized, qualified anchor nuts reduce procurement, qualification and inspection effort.

Related Standards

Key normative references that support EN 3768:2012 include:

• EN 2398, EN 2399, EN 3638, EN 3639 (heat-resisting steels)
• EN 2491 (MoS2 dry lubricants)
• EN 2424 (marking of aerospace products)
• ISO 3191, ISO 5855-2, ISO 5858, ISO 8788 (thread and dimensional standards)
• EN 9100 (quality management), EN 9133 (qualification for aerospace standard parts)

For procurement, design, and specification work, referencing EN 3768:2012 ensures consistent mechanical classing, material selection, surface treatment and traceable marking for aerospace anchor nut applications.

Standards Content (Sample)

SLOVENSKI STANDARD
01-september-2012
Aeronavtika - Zakovne matice, samovarovalne, enostranske, iz jekla, kadmirane,
mazane z MoS2 - Klasifikacija: 1100 MPa (pri temperaturi okolice)/315 °C
Aerospace series - Nuts, anchor, self-locking, one lug, fixed, reduced series, with
counterbore, in heat resisting steel, MoS2 lubricated - Classification: 1 100 MPa (at
ambient temperature)/315 °C
Luft- und Raumfahrt - Annietmuttern, selbstsichernd, einseitiger verkürzter Flansch, 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, simple patte, 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: EN 3768:2012
ICS:
49.030.30 Matice Nuts
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD
EN 3768
NORME EUROPÉENNE
EUROPÄISCHE NORM
March 2012
ICS 49.030.30
English Version
Aerospace series - Nuts, anchor, self-locking, one lug, fixed,
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, fixes, Luft- und Raumfahrt - Annietmuttern, selbstsichernd,
simple patte, série réduite, avec chambrage, en acier einseitiger verkürzter Flansch, mit zylindrischer
résistant à chaud, lubrifiés MoS2 - Classification: 1 100 Aussenkung, aus hochwarmfestem Stahl, MoS2-
MPa (à température ambiante)/315 °C geschmiert - Klasse: 1 100 MPa (bei Raumtemperatur)/315
°C
This European Standard was approved by CEN on 23 December 2011.

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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2012 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3768:2012: E
worldwide for CEN national Members.

Contents Page
Foreword .3
1 Scope .4
2 Normative references .4
3 Required characteristics .5
3.1 Configuration — Dimensions — Masses .5
3.2 Materials .5
3.3 Surface treatment .5
4 Designation .7
5 Marking .7
6 Technical specification .7

Foreword
This document (EN 3768:2012) 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 Standard has
received the approval of the National Associations and the Official Services of the member countries of ASD,
prior to its presentation to CEN.
This European Standard shall be given the status of a national standard, either by publication of an identical
text or by endorsement, at the latest by September 2012, and conflicting national standards shall be
withdrawn at the latest by September 2012.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. C
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