SIST EN 4309:2017
(Main)Aerospace series - Nuts, hexagon, self-locking by plastic ring, normal height, normal across flats, in alloy steel, cadmium plated - Classification: 900 MPa (at ambient temperature) / 120 °C
Aerospace series - Nuts, hexagon, self-locking by plastic ring, normal height, normal across flats, in alloy steel, cadmium plated - Classification: 900 MPa (at ambient temperature) / 120 °C
This European Standard specifies the characteristics of hexagonal nuts, self-locking by plastic ring, normal height, normal across flats, in alloy steel, cadmium plated.
Classification: 900 MPa / 120 °C
Luft- und Raumfahrt - Sechskantmuttern, selbstsichernd mit Plastikring, mit normaler Schlüsselweite, aus legiertem Stahl, verkadmet - Klasse: 900 MPa (bei Raumtemperatur) / 120 °C
Série aérospatiale - Écrous hexagonaux, à freinage interne par bague plastique, hauteur normale, surplats normaux, en acier allié, cadmiés - Classification : 900 MPa (à température ambiante) / 120 °C
Aeronavtika - Matice, šestrobe, samovarovalne s plastičnim obročem, normalno visoke, normalno prečno ploske, iz jeklene litine, kadmirane - Klasifikacija: 900 MPa (pri temperaturi okolice)/120 °C
Ta evropski standard določa lastnosti šestrobih matic, samovarovalnih s plastičnim obročem, normalne višine, normalno prečno ploskih, iz jeklene litine, kadmiranih.
Klasifikacija: 900 MPa/120 °C
General Information
- Status
- Published
- Publication Date
- 31-Jan-2017
- Technical Committee
- I13 - Imaginarni 13
- Current Stage
- 6060 - National Implementation/Publication (Adopted Project)
- Start Date
- 09-Jan-2017
- Due Date
- 16-Mar-2017
- Completion Date
- 01-Feb-2017
Relations
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
- Effective Date
- 28-Jan-2026
Overview
SIST EN 4309:2017 is a European Standard that specifies the characteristics and requirements for aerospace series hexagon self-locking nuts, featuring a plastic ring for locking capability. These nuts possess normal height and standard across flats, are manufactured from alloy steel, and have a cadmium-plated surface for enhanced durability. The standard further classifies these components for use in applications requiring strength up to 900 MPa at ambient temperature and thermal resistance up to 120 °C.
This standard is harmonized across Europe to meet the rigorous mechanical, dimensional, and surface requirements necessary for demanding aerospace and high-performance industrial applications.
Key Topics
- Product Description: Hexagon, self-locking nuts using a plastic ring, normal height/width, for aerospace.
- Material Requirements: Alloy steel body with a self-locking polyamide 6.6 plastic ring.
- Surface Treatment: Cadmium plating to improve corrosion protection and wear resistance.
- Mechanical Classification: Strength rated at 900 MPa (ambient temperature).
- Thermal Classification: Designed for reliable operation up to 120 °C.
- Dimensional and Tolerance Guidelines: Standardization of thread size, height, width across flats, and form as per referenced documents.
- Quality Assurance: Compliance with EN 9100 for aerospace quality management, and product qualification in line with EN 9133.
Applications
SIST EN 4309:2017 nuts are widely used in various aerospace and defense contexts due to their high strength, reliability, and secure fastening properties. Key application areas include:
- Aerospace Structures: Securing components in airframes, engine mounts, and landing gear assemblies where vibration resistance is vital.
- Avionics and Equipment: Fastening of sensitive equipment benefiting from the self-locking feature to prevent loosening due to shock or thermal expansion.
- Defense Industry: Use in military vehicles and hardware requiring high performance, consistent torque retention, and environmental resistance.
- Industrial Machinery: Suitable for high-performance industrial applications that demand robust and vibration-resistant fasteners.
These nuts are preferred where frequent dynamic loading, temperature fluctuations, and corrosion risks are present. The plastic ring ensures self-locking capability, reducing maintenance and enhancing operational safety.
Related Standards
To ensure comprehensive compliance and best practices in selection and use, the following related standards are referenced within SIST EN 4309:2017:
- EN 2424: Aerospace series – Marking requirements for aerospace products.
- EN 2133: Requirements for cadmium plating on steel fasteners.
- EN 9100: Quality management systems specifically for aviation, space, and defense organizations.
- EN 9133: Procedures for qualification of aerospace standard products.
- ISO 5855-2: Aerospace MJ thread dimensions for bolts and nuts.
- ISO 5858: Procurement specification for aerospace self-locking nuts with maximum temperature ≤ 235 °C.
- ISO 8788: Nut tolerances (form and position).
- TR 3823: Guidance on materials for hexagonal nuts in aerospace.
By adhering to SIST EN 4309:2017 and associated standards, designers and manufacturers can ensure product safety, compatibility, and reliability in critical aerospace and related applications.
Keywords: self-locking nuts, aerospace hex nuts, cadmium plated fasteners, EN 4309, high-strength alloy steel nuts, vibration-resistant fasteners, 900 MPa classification, 120 °C thermal resistance, European aviation standards.
Get Certified
Connect with accredited certification bodies for this standard
BUREAU VERITAS Certification Germany
Bureau Veritas certification in Germany.
Element Materials Technology
Materials testing and product certification.
AQMS Ltd.
AQMS provides ISO certification to SMEs across the UK.
Sponsored listings
Frequently Asked Questions
SIST EN 4309:2017 is a standard published by the Slovenian Institute for Standardization (SIST). Its full title is "Aerospace series - Nuts, hexagon, self-locking by plastic ring, normal height, normal across flats, in alloy steel, cadmium plated - Classification: 900 MPa (at ambient temperature) / 120 °C". This standard covers: This European Standard specifies the characteristics of hexagonal nuts, self-locking by plastic ring, normal height, normal across flats, in alloy steel, cadmium plated. Classification: 900 MPa / 120 °C
This European Standard specifies the characteristics of hexagonal nuts, self-locking by plastic ring, normal height, normal across flats, in alloy steel, cadmium plated. Classification: 900 MPa / 120 °C
SIST EN 4309:2017 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.
SIST EN 4309:2017 has the following relationships with other standards: It is inter standard links to SIST EN ISO 15792-1:2008, SIST EN 2133:2021, SIST EN 9133:2018, SIST EN 9100:2018, SIST EN 840-6:2004+A1:2008, SIST EN 2424:2008, SIST EN ISO 25178-71:2017. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
SIST EN 4309:2017 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)
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Aerospace series - Nuts, hexagon, self-locking by plastic ring, normal height, normal across flats, in alloy steel, cadmium plated - Classification: 900 MPa (at ambient temperature) / 120 °C49.030.30MaticeNutsICS:Ta slovenski standard je istoveten z:EN 4309:2016SIST EN 4309:2017en,fr,de01-marec-2017SIST EN 4309:2017SLOVENSKI
STANDARD
EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 4309
December
t r s x ICS
v {ä r u rä u r English Version
Aerospace series æ Nutsá hexagoná selfælocking by plastic ringá normal heightá normal across flatsá in alloy steelá cadmium plated æ ClassificaSérie aérospatiale æ Écrous hexagonauxá à freinage interne par bague plastiqueá hauteur normaleá surplats normauxá en acier alliéá cadmiés æ Classification ã
{ r r
Luftæ und Raumfahrt æ Sechskantmutterná selbstsichernd mit Plastikringá mit normaler Schlüsselweiteá aus legiertem Stahlá verkadmet æ This European Standard was approved by CEN on
s s March
t r s xä
egulations which stipulate the conditions for giving this European Standard the status of a national standard without any alterationä Upætoædate lists and bibliographical references concerning such national standards may be obtained on application to the CENæCENELEC Management Centre or to any CEN memberä
translation under the responsibility of a CEN member into its own language and notified to the CENæCENELEC Management Centre has the same status as the official versionsä
CEN members are the national standards bodies of Austriaá Belgiumá Bulgariaá Croatiaá Cyprusá Czech Republicá Denmarká Estoniaá Finlandá Former Yugoslav Republic of Macedoniaá Franceá Germanyá Greeceá Hungaryá Icelandá Irelandá Italyá Latviaá Lithuaniaá Luxembourgá Maltaá Netherlandsá Norwayá Polandá Portugalá Romaniaá Slovakiaá Sloveniaá Spainá Swedená Switzerlandá Turkey andUnited Kingdomä
EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre:
Avenue Marnix 17,
B-1000 Brussels
t r s x CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Membersä Refä Noä EN
v u r {ã t r s x ESIST EN 4309:2017
Page European foreword . 3 1 Scope . 4 2 Normative references . 4 3 Required characteristics . 4 4 Designation . 6 5 Marking . 7 6 Technical specification . 7
...