SIST EN 3646-004:2026

Aerospace series - Connectors, electrical, circular, bayonet coupling, operating temperature 175 °C or 200 °C continuous - Part 004: Receptacle, jam-nut mounting - Product standard

This document specifies the characteristics of the jam-nut mounted receptacles of the family of bayonet coupling circular connectors, intended for use in an operating temperature range of –65 °C to 175 °C or 200 °C continuous. It is applicable to models specified in Table 4. For contacts, filler plugs and rear accessories associated with this receptacle, see EN 3646-002. For plugs and protective covers, see EN 3646-008 and EN 3646-009 respectively.

Luft- und Raumfahrt - Elektrische Rundsteckverbinder mit Bajonettkupplung, Betriebstemperatur 175 °C oder 200 °C konstant - Teil 004: Fester Steckverbinder mit Mutternbefestigung - Produktnorm

Dieses Dokument legt die Eigenschaften von festen Steckverbindern mit Mutternbefestigung aus der Familie der Rundsteckverbinder mit Bajonettkupplung fest, die für den Einsatz im Betriebstemperaturbereich von −65 °C bis 175 °C oder 200 °C konstant vorgesehen sind.
Es ist für die in Tabelle 4 festgelegten Bauformen anwendbar.
Für zu diesem festen Steckverbinder zugehörige Kontakte, Blindstopfen und Endgehäuse siehe EN 3646 002. Für zugehörige freie Steckverbinder und Schutzkappen siehe EN 3646 008 bzw. EN 3646 009.

Série aérospatiale - Connecteurs électriques circulaires à accouplement par baïonnettes, température d'utilisation 175 °C ou 200 °C continu - Partie 004 : Embase à fixation par écrou - Norme de produit

Le présent document spécifie les caractéristiques des embases à fixation par écrou de la famille des connecteurs circulaires à accouplement par baïonnettes, destinés à une utilisation dans une plage de températures comprises entre −65 °C et 175 °C ou 200 °C continu.
Il est applicable aux modèles spécifiés dans le Tableau 4.
Pour les contacts, les obturateurs et les accessoires arrière associés à cette embase, voir l’EN 3646 002. Pour les fiches et les bouchons de vol, voir respectivement l’EN 3646 008 et l’EN 3646 009.

Aeronavtika - Konektorji, električni, okrogli, z bajonetnim spojem, neprekinjena delovna temperatura 175 °C ali 200 °C - 004. del: Vtičnica, pritrditev z matico - Standard izdelka

Ta dokument določa značilnosti vgradnih vtičnic z matico za pritrditev iz družine krožnih konektorjev z bajonetnim spojem, namenjenih za uporabo v temperaturnem območju od –65 °C do 175 °C ali 200 °C neprekinjeno. Uporablja se za modele, določene v Tabeli 4. Za kontakte, polnilne čepke in zadnje dodatke, povezane s to vtičnico, glejte EN 3646-002. Za vtikače in zaščitne pokrove glejte EN 3646-008 in EN 3646-009.

General Information

• Status: Published
• Public Enquiry End Date: 11-Jun-2024
• Publication Date: 01-Apr-2026
• ICS: 31.220.10 - Plug-and-socket devices. Connectors
• ICS: 49.060 - Aerospace electric equipment and systems
• Technical Committee: I13 - Imaginarni 13
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-Mar-2026
• Due Date: 23-May-2026
• Completion Date: 02-Apr-2026
• Ref Project: EN 3646-004:2026 - Aerospace series - Connectors, electrical, circular, bayonet coupling, operating temperature 175 °C or 200 °C continuous - Part 004: Receptacle, jam-nut mounting - Product standard

Relations

• Refers: SIST EN 3646-001:2016 - Aerospace series - Connectors, electrical, circular, bayonet coupling, operating temperature 175 °C or 200 °C continuous - Part 001: Technical specification
• Effective Date: 18-Mar-2026
• Referred By: SIST EN 3646-002:2026 - Aerospace series - Connectors, electrical, circular, bayonet coupling, operating temperature 175 °C or 200 °C continuous - Part 002: Specification of performance and contact arrangements
• Effective Date: 18-Mar-2026
• Referred By: SIST EN 3155-002:2024 - Aerospace series - Electrical contacts used in elements of connection - Part 002: List and utilization of contacts
• Effective Date: 04-Mar-2026
• Referred By: SIST EN 3660-066:2017 - Aerospace series - Cable outlet accessories for circular and rectangular electrical and optical connectors - Part 066: Cable outlet, style K, 90°, for heat shrinkable boot, shielded, sealed - Product standard
• Effective Date: 04-Mar-2026
• Referred By: SIST EN 3660-034:2017 - Aerospace series - Cable outlet accessories for circular and rectangular electrical and optical connectors - Part 034: Memory metal rings for the attachment of screens - Product standard
• Effective Date: 04-Mar-2026
• Referred By: SIST EN 3646-009:2015 - Aerospace series - Connectors, electrical, circular, bayonet coupling, operating temperature 175 °C or 200 °C continuous - Part 009: Protective cover for receptacle - Product standard
• Effective Date: 04-Mar-2026
• Referred By: SIST EN 3660-002:2009 - Aerospace series - Cable outlet accessories for circular and rectangular electrical and optical connectors - Part 002: Index of product standards
• Effective Date: 04-Mar-2026
• Referred By: SIST EN 3646-008:2009 - Aerospace series - Connectors, electrical, circular, bayonet coupling, operating temperature 175 °C or 200 °C continuous - Part 008: Plug - Product standard
• Effective Date: 04-Mar-2026
• Referred By: SIST EN 3646-002:2009 - Aerospace series - Connectors, electrical, circular, bayonet coupling, operating temperature 175 °C or 200 °C continuous - Part 002: Specification of performance and contact arrangements
• Effective Date: 04-Mar-2026
• Referred By: SIST EN 3646-009:2009 - Aerospace series - Connectors, electrical, circular, bayonet coupling, operating temperature 175 °C or 200 °C continuous - Part 009: Protective cover for receptacle - Product standard
• Effective Date: 04-Mar-2026
• Referred By: SIST EN 3660-002:2016 - Aerospace series - Cable outlet accessories for circular and rectangular electrical and optical connectors - Part 002: Index of product standards
• Effective Date: 04-Mar-2026
• Revises: SIST EN 3646-004:2016 - Aerospace series - Connectors, electrical, circular, bayonet coupling, operating temperature 175 °C or 200 °C continuous - Part 004: Receptacle, jam-nut mounting - Product standard
• Effective Date: 25-Oct-2023

Overview

SIST EN 3646-004:2026 is a European product standard, issued by CEN, within the aerospace series. It specifies the characteristics for jam-nut mounted receptacles in the family of bayonet coupling circular electrical connectors. Designed for demanding environments, these connectors support continuous operating temperatures of –65 °C to 175 °C or 200 °C. This standard ensures compatibility and performance for aerospace electrical systems, covering key requirements such as dimensions, materials, mounting details, and marking. SIST EN 3646-004:2026 supersedes the 2015 edition, introducing updates like the addition of six equally spaced holes in the jam nut for locking wire.

Key Topics

• Jam-Nut Mounting: Defines the requirements for receptacles that use a jam-nut (threaded nut) for secure panel attachment, critical for maintaining connection integrity in vibration-prone environments.
• Bayonet Coupling Mechanism: Details the use of bayonet-style mating for fast, reliable connector coupling and decoupling, commonly utilized in aerospace for their robustness and ease of use.
• Continuous High Temperature Operation: Specifies operating temperature ranges up to 175 °C or 200 °C, supporting the thermal demands found in aircraft and aerospace systems.
• Standardized Dimensions and Torque: Includes essential dimensional data, panel cut-outs, and specified tightening torques, ensuring interchangeability and proper installation across manufacturers.
• Material and Plating: Describes housing options such as black anodized or nickel-plated aluminum alloy, and performance features like corrosion resistance and salt spray protection.
• Marking and Traceability: Sets requirements for product and packaging marking, aiding in traceability and verification throughout the aerospace supply chain.

Applications

SIST EN 3646-004:2026 jam-nut mounted receptacles are used across the aerospace sector, ensuring reliable electrical connections in environments subject to high vibration, contaminants, and extreme temperature variations. Practical uses include:

• Commercial and Military Aircraft: Employed in avionics, power distribution, lighting, and instrumentation where robust, quick-mating circular connectors are essential.
• Spacecraft and Aerospace Systems: Suitable for use in satellites and launch vehicles due to their tight sealing and high-performance characteristics.
• Defense Vehicles and Field Equipment: The high reliability and secure mounting are valuable in military ground vehicles and advanced defense electronics.
• Maintenance and Upgrades: Standardized features ensure seamless integration during maintenance or system upgrades, reducing downtime and complexity.

Organizations benefit from using SIST EN 3646-004:2026 compliant connectors by ensuring:

• Interchangeability between suppliers and platforms
• Enhanced reliability and safety in critical electrical connections
• Simplified procurement and inventory processes due to standardization

Related Standards

For complete system compatibility and to address all connection needs, consider these related standards within the EN 3646 series:

• EN 3646-001: General technical specification for bayonet coupling circular connectors, offering overarching requirements for the series.
• EN 3646-002: Specification of performance and contact arrangements, covering associated contacts, filler plugs, and rear accessories.
• EN 3646-008: Product standard for the corresponding plug connectors.
• EN 3646-009: Product standard for protective covers designed for these receptacles.
• EN 3155-002: Lists and utilization of electrical contacts used with these connectors.
• ISO 3161: Specifies general requirements and limit dimensions for UNJ threads used in aerospace connectors.

By referencing the appropriate standards, engineering teams can ensure full compliance and optimized performance of electrical interconnections in aerospace applications.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2026
Aeronavtika - Konektorji, električni, okrogli, z bajonetnim spojem, neprekinjena
delovna temperatura 175 °C ali 200 °C - 004. del: Vtičnica, pritrditev z matico -
Standard izdelka
Aerospace series - Connectors, electrical, circular, bayonet coupling, operating
temperature 175 °C or 200 °C continuous - Part 004: Receptacle, jam-nut mounting -
Product standard
Luft- und Raumfahrt - Elektrische Rundsteckverbinder mit Bajonettkupplung,
Betriebstemperatur 175 °C oder 200 °C konstant - Teil 004: Fester Steckverbinder mit
Mutternbefestigung - Produktnorm
Série aérospatiale - Connecteurs électriques circulaires à accouplement par baïonnettes,
température d'utilisation 175 °C ou 200 °C continu - Partie 004 : Embase à fixation par
écrou - Norme de produit
Ta slovenski standard je istoveten z: EN 3646-004:2026
ICS:
31.220.10 Vtiči in vtičnice, konektorji Plug-and-socket devices.
Connectors
49.060 Letalska in vesoljska Aerospace electric
električna oprema in sistemi equipment and systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN 3646-004
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2026
EUROPÄISCHE NORM
ICS 49.060 Supersedes EN 3646-004:2015
English Version
Aerospace series - Connectors, electrical, circular, bayonet
coupling, operating temperature 175 °C or 200 °C
continuous - Part 004: Receptacle, jam-nut mounting -
Product standard
Série aérospatiale - Connecteurs électriques circulaires Luft- und Raumfahrt - Elektrische Rundsteckverbinder
à accouplement par baïonnettes, température mit Bajonettkupplung, Betriebstemperatur 175 °C oder
d'utilisation 175 °C ou 200 °C continu - Partie 004 : 200 °C konstant - Teil 004: Fester Steckverbinder mit
Embase à fixation par écrou - Norme de produit Mutternbefestigung - Produktnorm
This European Standard was approved by CEN on 3 November 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
© 2026 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 3646-004:2026 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Required characteristics . 4
4.1 Dimensions and mass . 4
4.2 Tightening torque of attachment nut . 6
4.3 Panel cut-out . 7
4.4 Material and surface treatment . 7
4.5 Main general characteristics . 7
4.6 Possible combinations of plugs and receptacles . 8
5 Designation . 8
6 Marking . 9
6.1 General. 9
6.2 Marking on the product . 9
6.3 Marking on the individual packaging . 9
7 Technical specification . 9
Bibliography . 10

European foreword
This document (EN 3646-004:2026) 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 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 August 2026, and conflicting national standards shall be
withdrawn at the latest by August 2026.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 3646-004:2015.
EN 3646-004:2015:
— possibility to have six equally spaced holes in the jam nut for locking wire added;
— Figure 1 updated.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to impleme
...