SIST EN IEC 61076-2-104:2026

Connectors for electrical and electronic equipment - Product requirements - Part 2-104: Circular connectors - Detail specification for circular connectors with M8 screw-locking or snap-locking (IEC 61076-2-104:2026)

This part of IEC 61076 describes 3-way to 12-way circular connectors with M8 screw-locking or with nominal ∅ 8 mm snap-locking, for connection of automation devices, for signal and power transmission up to 50 V AC / 60 V DC rated voltage and up to 4 A rated current.
These connectors are available as fixed or free connectors, either rewirable or non-rewirable. Male connectors have round contacts ∅ 0,48 mm, ∅ 0,6 mm, ∅ 0,7 mm and ∅ 1,0 mm, depending on the number of ways and coding, with all contacts being of the same size.
The different codings prevent the mating of differently coded male and female connectors.
NOTE M8 is the dimension of the thread of the screw locking mechanism of these circular connectors.

Lichtwellenleiterkabel - Teil 1-104: Fachgrundspezifikation - Grundlegende Prüfverfahren für optische Kabel - Mechanische Prüfverfahren - Schlag, Verfahren E4 (IEC 61076-2-104:2026)

Connecteurs pour équipements électroniques - Exigences de produit - Partie 2-104: Connecteurs circulaires - Spécification particulière pour les connecteurs circulaires m8 à vis ou à encliquetage (IEC 61076-2-104:2026)

Konektorji za električno in elektronsko opremo - Zahteve za izdelek - 2-104. del: Okrogli konektorji - Podrobna specifikacija za okrogle konektorje z vijačnim M8 ali zaskočnim zaklepanjem (IEC 61076-2-104:2026)

Ta del standarda IEC 61076 opisuje krožne konektorje s 3 do 12 priključki z M8 vijačnim zaklepom ali z nazivnim premerom ∅ 8 mm z zaskočnim zaklepom, namenjene za povezovanje avtomatizacijskih naprav, za prenos signalov in moči do nazivnih napetosti 50 V AC / 60 V DC in do nazivnega toka 4 A.
Ti konektorji so na voljo kot fiksni ali prosti konektorji, bodisi za ponovno ožičenje bodisi brez možnosti ponovnega ožičenja. Moški konektorji imajo okrogle kontakte premera ∅ 0,48 mm, ∅ 0,6 mm, ∅ 0,7 mm in ∅ 1,0 mm, odvisno od števila priključkov in kodiranja, pri čemer so vsi kontakti enake velikosti.
Različna kodiranja preprečujejo združevanje različno kodiranih moških in ženskih konektorjev.
OPOMBA M8 je dimenzija navoja mehanizma vijačnega zaklepa teh krožnih konektorjev.

General Information

• Status: Published
• Public Enquiry End Date: 31-Dec-2024
• Publication Date: 09-Apr-2026
• ICS: 31.220.10 - Plug-and-socket devices. Connectors
• Technical Committee: I11 - Imaginarni 11
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 31-Mar-2026
• Due Date: 05-Jun-2026
• Completion Date: 10-Apr-2026
• Ref Project: EN IEC 61076-2-104:2026 - Connectors for electrical and electronic equipment - Product requirements - Part 2-104: Circular connectors - Detail specification for circular connectors with M8 screw-locking or snap-locking

Relations

• Replaces: SIST EN 61076-2-104:2014 - Connectors for electronic equipment - Product requirements -- Part 2-104: Circular connectors - Detail specification for circular connectors with M8 screw-locking or snap-locking
• Effective Date: 01-May-2026
• Refers: SIST EN IEC 60664-1:2020 - Insulation coordination for equipment within low-voltage supply systems - Part 1: Principles, requirements and tests (IEC 60664-1:2020)
• Effective Date: 10-Mar-2026
• Refers: SIST EN 62197-1:2006 - Connectors for electronic equipment - Quality assessment requirements -- Part 1: Generic specification
• Effective Date: 10-Mar-2026
• Refers: SIST EN 61984:2009 - Connectors - Safety requirements and tests (IEC 61984:2008)
• Effective Date: 10-Mar-2026
• Refers: SIST EN IEC 60352-3:2020 - Solderless connections - Part 3: Accessible insulation displacement (ID) connections - General requirements, test methods and practical guidance (IEC 60352-3:2020)
• Effective Date: 10-Mar-2026
• Refers: SIST EN 60512-1-2:2003 - Connectors for electronic equipment - Tests and measurements -- Part 1-2: General examination - Test 1b: Examination of dimension and mass
• Effective Date: 10-Mar-2026
• Refers: SIST EN 60512-13-5:2006 - Connectors for electronic equipment - Tests and measurements -- Part 13-5: Mechanical operation tests - Test 13e: Polarizing and keying method
• Effective Date: 10-Mar-2026
• Refers: SIST EN 60512-13-2:2006 - Connectors for electronic equipment - Tests and measurements -- Part 13-2: Mechanical operation tests - Test 13b: Insertion and withdrawal forces
• Effective Date: 10-Mar-2026
• Refers: SIST EN 60512-4-1:2004 - Connectors for electronic equipment - Tests and measurements -- Part 4-1: Voltage stress tests - Test 4a: Voltage proof
• Effective Date: 10-Mar-2026
• Refers: SIST EN 60512-2-1:2003 - Connectors for electronic equipment - Tests and measurements -- Part 2-1: Electrical continuity and contact resistance tests - Test 2a: Contact resistance - Millivolt level method
• Effective Date: 10-Mar-2026
• Refers: SIST EN 60512-6-3:2003 - Connectors for electronic equipment - Tests and measurements -- Part 6-3: Dynamic stress tests - Test 6c: Shock
• Effective Date: 10-Mar-2026
• Refers: SIST EN IEC 60512-1:2019 - Connectors for electrical and electronic equipment - Tests and measurements - Part 1: Generic specification (IEC 60512-1:2018)
• Effective Date: 10-Mar-2026
• Refers: SIST EN 60999-1:2001 - Connecting devices - Electrical copper conductors - Safety requirements for screw-type and screwless-type clamping units -- Part 1: General requirements and particular requirements for clamping units for conductors from 0,2 mm² up to 35 mm² (included)
• Effective Date: 10-Mar-2026
• Refers: SIST EN 60068-1:2014 - Environmental testing - Part 1: General and guidance
• Effective Date: 10-Mar-2026
• Refers: SIST EN 60529:1997/A2:2014 - Degrees of protection provided by enclosures (IP Code)
• Effective Date: 10-Mar-2026

Overview

FprEN IEC 61076-2-104:2025 (prEN IEC 61076-2-104:2024) is the detail specification for M8 circular connectors used in electronic equipment. Published under CLC adoption of the IEC series, this part of IEC 61076 defines product requirements for circular connectors with M8 screw‑locking or snap‑locking. The document covers dimensional drawings, contact arrangements, mechanical and electrical characteristics, test schedules and environmental/marking requirements. Note: the CDV (Committee Draft for Vote) indicates the document was under parallel IEC/CENELEC voting and may be subject to change.

Key topics and technical requirements

• Connector types and styles: Detailed dimensional tables and figures for multiple fixed and free connector styles (examples: BM, CM, EM, EF for fixed; JM, KM, NM, OM, etc. for free/rewirable and non‑rewirable variants).
• Contact arrangements and codings: Standardized pin layouts and coding (A‑coding for 3, 4, 6, 8‑way; B‑coding for 5‑way; C‑coding for 12‑way) with front/side views and contact position diagrams.
• Electrical characteristics: Requirements and test methods for rated insulation voltage, rated impulse voltage, current‑carrying capacity, contact resistance and insulation resistance.
• Mechanical characteristics: Insertion/withdrawal forces, contact retention, polarizing/coding methods, and engagement/mating dimensions. Gauges and retention force specifications are included.
• Environmental and safety: Classification into climatic categories, creepage and clearance distances, degree of protection (IP code), vibration and shock resistance, marking of insulating materials (plastics), and other environmental considerations.
• Termination and assembly: Recommended methods of termination for rewirable connectors and wiring arrangements for test specimens.
• Testing: Basic and full test schedules, arrangements for contact resistance measurement and dynamic stress testing.

Applications

This standard is directly applicable to the design, manufacture and testing of M8 circular connectors commonly used in:

• Industrial automation (sensors, actuators, field devices)
• Machine control and instrumentation
• Factory-floor cabling and modular equipment interfaces
• Embedded and OEM electronic equipment requiring compact, reliable circular connections

Adherence ensures mechanical interchangeability, electrical performance, environmental robustness and interoperability across suppliers.

Who uses this standard

• Connector and cable assembly manufacturers
• Product and hardware designers (control systems, sensors, robotics)
• Compliance and test laboratories
• Procurement and quality engineers specifying connector performance
• Standards committees and regulatory bodies

Related standards

• IEC 61076‑1 (compatibility levels and general connector requirements) - referenced for compatibility
• IEC SC 48B publications (electrical connectors committee)
• ICS class 31.220.10 (plug-and-socket devices, connectors)

Keywords: IEC 61076-2-104, FprEN IEC 61076-2-104:2025, M8 circular connectors, screw-locking, snap-locking, connector specification, connector standards.

Standards Content (Sample)

SLOVENSKI STANDARD
01-maj-2026
Nadomešča:
SIST EN 61076-2-104:2014
Konektorji za električno in elektronsko opremo - Zahteve za izdelek - 2-104. del:
Okrogli konektorji - Podrobna specifikacija za okrogle konektorje z vijačnim M8 ali
zaskočnim zaklepanjem (IEC 61076-2-104:2026)
Connectors for electrical and electronic equipment - Product requirements - Part 2-104:
Circular connectors - Detail specification for circular connectors with M8 screw-locking or
snap-locking (IEC 61076-2-104:2026)
Lichtwellenleiterkabel - Teil 1-104: Fachgrundspezifikation - Grundlegende Prüfverfahren
für optische Kabel - Mechanische Prüfverfahren - Schlag, Verfahren E4 (IEC 61076-2-
104:2026)
Connecteurs pour équipements électroniques - Exigences de produit - Partie 2-104:
Connecteurs circulaires - Spécification particulière pour les connecteurs circulaires m8 à
vis ou à encliquetage (IEC 61076-2-104:2026)
Ta slovenski standard je istoveten z: EN IEC 61076-2-104:2026
ICS:
31.220.10 Vtiči in vtičnice, konektorji Plug-and-socket devices.
Connectors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 61076-2-104

NORME EUROPÉENNE
EUROPÄISCHE NORM March 2026
ICS 31.220.10 Supersedes EN 61076-2-104:2014
English Version
Connectors for electrical and electronic equipment - Product
requirements - Part 2-104: Circular connectors - Detail
specification for circular connectors with M8 screw-locking or
snap-locking
(IEC 61076-2-104:2026)
Connecteurs pour équipements électroniques - Exigences Steckverbinder für elektronische Einrichtungen -
de produit - Partie 2-104: Connecteurs circulaires - Produktanforderungen - Teil 2-104: Rundsteckverbinder -
Spécification particulière pour les connecteurs circulaires Bauartspezifikation für Rundsteckverbinder M8 mit
m8 à vis ou à encliquetage Schraub-oder Rastverriegelung
(IEC 61076-2-104:2026) (IEC 61076-2-104:2026)
This European Standard was approved by CENELEC on 2026-03-16. CENELEC 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 CENELEC 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 CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Türkiye and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2026 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 61076-2-104:2026 E

European foreword
The text of document 48B/3188/FDIS, future edition 3 of IEC 61076-2-104, prepared by SC 48B
"Electrical connectors" of IEC/TC 48 "Electrical connectors and mechanical structures for electrical
and electronic equipment" was submitted to the IEC-CENELEC parallel vote and approved by
CENELEC as EN IEC 61076-2-104:2026.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2027-03-31
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2029-03-31
document have to be withdrawn
This document supersedes EN 61076-2-104:2014 and all of its amendments and corrigenda (if any).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 61076-2-104:2026 was approved by CENELEC as a
European Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standard indicated:
IEC 60512-5-2 NOTE Approved as EN 60512-5-2
IEC 61076-2 NOTE Approved as EN IEC 61076-2
IEC 61076-2-114 NOTE Approved as EN IEC 61076-2-114
ISO 11469 NOTE Approved as EN ISO 11469
ISO 21920-1:2021 NOTE Approved as EN ISO 21920-1:2022 (not modified)
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments)
applies.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod),
the relevant EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available
here: www.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60050-581 - International Electrotechnical Vocabulary - - -
Part 581: Electromechanical components
for electronic equipment
IEC 60068-1 - Environmental testing - Part 1: General EN 60068-1 -
and guidance
IEC 60352-2 - Solderless connections - Part 2: Crimped EN IEC 60352-2 -
connections - General requirements, test
methods and practical guidance
IEC 60352-3 - Solderless connections - Part 3: Accessible EN IEC 60352-3 -
insulation displacement (ID) connections -
General requirements, test methods and
practical guidance
IEC 60352-4 - Solderless connections - Part 4: Non- EN IEC 60352-4 -
accessible insulation displacement (ID)
connections - General requirements, test
methods and practical guidance
IEC 60352-5 - Solderless connections - Part 5: Press-in EN IEC 60352-5 -
connections - General requirements, test
methods and practical guidance
IEC 60352-6 - Solderless connections - Part 6: Insulation EN IEC 60352-6 -
piercing connections - General
requirements, test methods and practical
guidance
IEC 60352-7 - Solderless connections - Part 7: Spring EN IEC 60352-7 -
clamp connections - General requirements,
test methods and practical guidance
IEC 60352-9 - Solderless connections - Part 9: EN IEC 60352-9 -
Ultrasonically welded connections -
General requirements, test methods and
practical guidance
IEC 60512 series Connectors for electrical and electronic EN IEC 60512 series
equipment - Tests and measurements -
Part 1: Generic specification
IEC 60512-1 - Connectors for electrical and electronic EN IEC 60512-1 -
equipment - Tests and measurements -
Part 1: Generic specification
IEC 60512-1-2 - Connectors for electronic equipment - EN 60512-1-2 -
Tests and measurements - Part 1-2:
General examination - Test 1b:
Examination of dimension and mass
IEC 60512-2-1 - Connectors for electronic equipment - EN 60512-2-1 -
Tests and measurements - Part 2-1:
Electrical continuity and contact resistance
tests - Test 2a: Contact resistance -
Millivolt level method
IEC 60512-3-1 - Connectors for electronic equipment - EN 60512-3-1 -
Tests and measurements - Part 3-1:
Insulation tests - Test 3a: Insulation
resistance
IEC 60512-4-1 - Connectors for electronic equipment - EN 60512-4-1 -
Tests and measurements - Part 4-1:
Voltage stress tests - Test 4a: Voltage
proof
IEC 60512-6-3 - Connectors for electronic equipment - EN 60512-6-3 -
Tests and measurements - Part 6-3:
Dynamic stress tests - Test 6c: Shock
IEC 60512-6-4 - Connectors for electronic equipment - EN 60512-6-4 -
Tests and measurements - Part 6-4:
Dynamic stress tests - Test 6d: Vibration
(sinusoidal)
IEC 60512-9-1 - Connectors for electronic equipment - EN 60512-9-1 -
Tests and measurements - Part 9-1:
Endurance tests - Test 9a: Mechanical
operation
IEC 60512-13-2 - Connectors for electronic equipment - EN 60512-13-2 -
Tests and measurements - Part 13-2:
Mechanical operation tests - Test 13b:
Insertion and withdrawal forces
IEC 60512-13-5 - Connectors for electronic equipment - EN 60512-13-5 -
Tests and measurements - Part 13-5:
Mechanical operation tests - Test 13e:
Polarizing and keying method
IEC 60529 1989 Degrees of protection provided by EN 60529 1991
enclosures (IP Code)
- - + corrigendum May 1993
+ A1 1999 + A1 2000
+ A2 2013 + A2 2013
IEC 60664-1 2020 Insulation coordination for equipment EN IEC 60664-1 2020
within low-voltage supply systems - Part 1:
Principles, requirements and tests
IEC 60999-1 - Connecting devices - Electrical copper EN 60999-1 -
conductors - Safety requirements for
screw-type and screwless-type clamping
units - Part 1: General requirements and
particular requirements for clamping units
for conductors from 0,2 mm2 up to 35 mm2
(included)
IEC 61076-1 - Connectors for electronic equipment - EN 61076-1 -
Product requirements - Part 1: Generic
specification
IEC 61984 2008 Connectors - Safety requirements and EN 61984 2009
tests
IEC 62197-1 - Connectors for electronic equipment - EN 62197-1 -
Quality assessment requirements - Part 1:
Generic specification
IEC 61076-2-104 ®
Edition 3.0 2026-02
INTERNATIONAL
STANDARD
Connectors for electrical and electronic equipment - Product requirements -
Part 2-104: Circular connectors - Detail specification for circular connectors with
M8 screw-locking or snap-locking
ICS 31.220.10  ISBN 978-2-8327-1026-5

IEC 61076-2-104:2026-02(en)
IEC 61076-2-104:2026 © IEC 2026
CONTENTS
FOREWORD . 5
1 Scope . 8
2 Normative references . 8
3 Terms and definitions . 9
4 Technical information . 10
4.1 Recommended method of termination for connectors. 10
4.2 Connector coding, number of contacts, ratings and characteristics . 10
4.3 Systems of levels. 10
4.3.1 Performance level . 10
4.3.2 Compatibility levels, according to IEC 61076-1 . 10
4.4 Classification into climatic categories . 10
4.5 Creepage and clearance distances . 11
4.6 Current-carrying capacity . 11
4.7 Marking . 11
4.8 Safety aspects . 11
5 Dimensional information . 11
5.1 General . 11
5.2 Fixed connectors . 12
5.2.1 General. 12
5.2.2 Style EM . 12
5.2.3 Styles EF1 and EF2 . 13
5.3 Free connectors . 15
5.3.1 General. 15
5.3.2 Style JM . 16
5.3.3 Style KM . 16
5.3.4 Style NM . 17
5.3.5 Style OM . 17
5.3.6 Style LM . 19
5.3.7 Style MM . 20
5.3.8 Style JF . 21
5.3.9 Style KF . 21
5.3.10 Style NF . 22
5.3.11 Style QF . 23
5.3.12 Style LF . 24
5.3.13 Style MF . 25
5.4 Interface dimensions . 26
5.4.1 Pin front and side view A-coding 3-way . 26
5.4.2 Pin front and side view A-coding 4-way . 27
5.4.3 Pin front and side view A-coding 6-way . 28
5.4.4 Pin front and side view A-coding 8-way . 30
5.4.5 Pin front and side view B-coding 5-way . 31
5.4.6 Pin front and side view C-coding, 12-way . 33
5.4.7 Pin side view for snap- and screw-, snap- and screw-locking . 35
5.5 Engagement (mating) information . 37
5.6 Gauges. 39
5.6.1 Sizing gauges and retention force gauges . 39
6 Characteristics . 40
IEC 61076-2-104:2026 © IEC 2026
6.1 General . 40
6.2 Pin assignment and other definitions . 40
6.3 Classification into climatic categories . 40
6.4 Electrical characteristics . 41
6.4.1 Rated insulation voltage – Rated impulse voltage – Pollution degree . 41
6.4.2 Voltage proof . 41
6.4.3 Current-carrying capacity . 42
6.4.4 Contact resistance . 42
6.4.5 Insulation resistance . 42
6.5 Mechanical characteristics . 42
6.5.1 Mechanical operation . 42
6.5.2 Insertion and withdrawal forces . 43
6.5.3 Contact retention in insert . 43
6.5.4 Polarizing and coding method . 43
6.6 Other characteristics . 44
6.6.1 Vibration (sinusoidal). 44
6.6.2 Shock . 44
6.6.3 Degree of protection provided by enclosures (IP code) . 44
6.7 Environmental aspects - marking of insulation material (plastics) . 44
7 Test schedule . 44
7.1 General . 44
7.1.1 General aspects. 44
7.1.2 Climatic category . 44
7.1.3 Creepage and clearance distances . 44
7.1.4 Arrangement for contact resistance measurement . 45
7.1.5 Arrangement for dynamic stress tests . 46
7.1.6 Wiring of specimens . 47
7.2 Test schedules . 47
7.2.1 Basic (minimum) test schedule . 47
7.2.2 Full test schedule . 47
Annex A (informative) Recommended outer diameter of the female connector body. 56
Annex B (informative) Orientation of the cable outlet in relation to coding . 57
Annex C (normative) Dimension of connector inserts . 58
C.1 General . 58
C.2 Connector insert, with male contacts dip solder long version with screw- and
snap-locking. 58
C.3 Connector insert, with male contacts dip solder, short version with screw-
and snap-locking . 59
Bibliography . 60

Figure 1 – Fixed connector with wires, male contacts, and single hole mounting . 12
Figure 2 – Fixed connector with wires, female contacts, and single hole mounting . 13
Figure 3 – Fixed connector with wires, female contacts, and single hole mounting . 14
Figure 4 – Rewirable connector, male contacts, straight version with screw-locking. 16
Figure 5 – rewirable connector, male contacts, right angled version with screw-locking . 16
Figure 6 – non-rewirable connector, male contacts, straight version with screw- and
snap-locking . 17
Figure 7 – non-rewirable connector, male contacts, straight version with snap-locking . 17
IEC 61076-2-104:2026 © IEC 2026
Figure 8 – non-rewirable connector, male contacts, angled version with snap-locking . 18
Figure 9 – Non-rewirable connector, male contacts, straight version with screw-locking . 19
Figure 10 – non-rewirable connector, male contacts, right angled version with screw-
locking . 20
Figure 11 – Rewirable connector, female contacts, straight version with screw-locking . 21
Figure 12 – rewirable connector, female contacts, right angled version, with screw-
locking . 21
Figure 13 – Non-rewirable connector, female contacts, straight version with snap-
locking . 22
Figure 14 – Non-rewirable connector, female contacts, right angled version with snap-
locking . 23
Figure 15 – Non-rewirable connector, female contacts, straight version, with screw-
locking . 24
Figure 16 – Non-rewirable connector, female contacts, right angled version, with
screw-locking . 25
Figure 17 – Pin front and side view A-coding, 3-way . 26
Figure 18 – Contact position A-coding, 3-way, front view . 26
Figure 19 – Pin front and side view A-coding, 4-way . 27
Figure 20 – Contact position A-coding, 4-way, front view . 28
Figure 21 – Pin front and side view A-coding, 6-ways . 28
Figure 22 – Contact position A-coding, 6-way, front view . 29
Figure 23 – Pin front and side view A-coding, 8-ways . 30
Figure 24 – Contact position A-coding, 8-way, front view . 31
Figure 25 – Pin front and side view B-coding, 5-ways . 31
Figure 26 – Contact position B-coding 5-way, front view . 32
Figure 27 – Pin front and side view C-coding, 12-ways . 33
Figure 28 – Contact position C-coding 12-way, front view . 34
Figure 29 – Pin side view snap- and screw-, snap- and screw-locking . 35
Figure 30 – Engagement (mating) information . 37
Figure 31 – Gauge information . 39
Figure 32 – Contact resistance arrangement . 45
Figure 33 – Dynamic stress test arrangement . 46
Figure A.1 – Diameter of the female connector body, coding variant A . 56
Figure A.2 – Shape of the female connector body, coding variant B . 56
Figure A.3 – Diameter of the female connector body, coding variant C . 56
Figure B.1 – Orientation of cable outlet in relation to the coding – Free connectors
according to Table 6 . 57
Figure C.1 – Connector insert, with male contacts, dip solder long version with screw-
and snap-locking . 58
Figure C.2 – Connector insert, with male contacts, dip solder short version with screw-
and snap-locking . 59

Table 1 – Ratings of connectors . 10
Table 2 – Styles of fixed connectors . 12
Table 3 – Dimensions of style EM, Figure 1 . 13
Table 4 – Dimensions of style EF1, Figure 2 . 14
IEC 61076-2-104:2026 © IEC 2026
Table 5 – Dimensions of style EF2, Figure 3 . 15
Table 6 – Styles of free connectors . 15
Table 7 – Dimensions of style JM, Figure 4 . 16
Table 8 – Dimensions of style KM, Figure 5 . 17
Table 9 – Dimensions of style NM, Figure 6 . 17
Table 10 – Dimensions of style OM, Figure 7 . 18
Table 11 – Dimensions of style PM, Figure 8 . 18
Table 12 – Dimensions of style LM, Figure 9 . 19
Table 13 – Dimensions of style MM, Figure 10. 20
Table 14 – Dimensions of style JF, Figure 11 . 21
Table 15 – Dimensions of style KF, Figure 12 . 22
Table 16 – Dimensions of style NF, Figure 13. 22
Table 17 – Dimensions of style QF, Figure 14 . 23
Table 18 – Dimensions of style LF, Figure 15 . 24
Table 19 – Dimensions of style MF, Figure 16 . 25
Table 20 – Pin front and side view A-coding, 3-way. 26
Table 21 – Dimensions for Figure 19 . 27
Table 22 – Dimensions for Figure 21 . 29
Table 23 – Dimensions for Figure 23 . 30
Table 24 – Dimensions for Figure 25 . 32
Table 25 – Dimensions for Figure 27 . 33
Table 26 – Dimensions for Figure 29 . 36
Table 27 – Connectors dimensions in mated and locked position . 38
Table 28 – Gauges . 40
Table 29 – Climatic category . 40
Table 30 – Rated insulation voltage – Rated impulse voltage – Pollution degree . 41
Table 31 – Voltage proof . 41
Table 32 – Current-carrying capacity . 42
Table 33 – Number of mechanical operations . 43
Table 34 – Insertion and withdrawal forces. 43
Table 35 – Number of test specimens . 47
Table 36 – Test group P . 48
Table 37 – Test group AP . 49
Table 38 – Test group BP . 51
Table 39 – Test group CP. 53
Table 40 – Test group DP. 54
Table 41 – Test group EP . 54
Table 42 – Test group NP. 55
Table C.1 – Dimensions of connector insert, Figure C.1 . 58
Table C.2 – Connector insert, with male contacts, dip solder short version with screw-
and snap locking . 59

IEC 61076-2-104:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Connectors for electrical and electronic equipment -
Product requirements -
Part 2-104: Circular connectors - Detail specification for circular
connectors with M8 screw-locking or snap-locking

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC Publication(s)"). Their
preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with
may participate in this preparatory work. International, governmental and non-governmental organizations liaising
with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for
Standardization (ISO) in accordance with conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 61076-2-104 has been prepared by subcommittee 48B: Electrical connectors, of IEC
technical committee 48: Electrical connectors and mechanical structures for electrical and
electronic equipment. It is an International Standard.
This third edition cancels and replaces the second edition published in 2014. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The structure of this document has been adapted to the new IEC template for standards.
New subclauses have been added. Clause 5 and Clause 6 have been updated.
b) The mating face for a M8 12-pole connector has been added.
IEC 61076-2-104:2026 © IEC 2026
c) Annex B Orientation of cable outlet in relation to coding has been added.
d) The styles for connector inserts have been moved to the normative Annex C.
The text of this International Standard is based on the following documents:
Draft Report on voting
48B/3188/FDIS 48B/3194/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
A list of all parts of the IEC 61076 series, published under the general title Connectors for
electrical and electronic equipment - Product requirements, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
– reconfirmed,
– withdrawn, or
– revised.
IEC 61076-2-104:2026 © IEC 2026
IEC SC 48B – Electrical connectors IEC 61076-2-104 Ed 3
Specification available from:
IEC General secretariat or from the addresses shown on the inside
cover.
Electronic components of assessed quality in accordance with:
IEC 61076-1
Circular connectors M8 (screw-
locking) – diameter 8 mm (snap-
locking)
3 to 12 way
Male and female contacts
Male and female connectors
Rewirable – Non-rewirable
Free cable connectors straight and
right angled
Fixed connectors -flange mounting
and single hole mounting
Connector insert
IEC 61076-2-104:2026 © IEC 2026
1 Scope
This part of IEC 61076 describes 3-way to 12-way circular connectors with M8 screw-locking or
with nominal ∅ 8 mm snap-locking, for connection of automation devices, for signal and power
transmission up to 50 V AC / 60 V DC rated voltage and up to 4 A rated current.
These connectors are available as fixed or free connectors, either rewirable or non-rewirable.
Male connectors have round contacts ∅ 0,48 mm, ∅ 0,6 mm, ∅ 0,7 mm and ∅ 1,0 mm,
depending on the number of ways and coding, with all contacts being of the same size.
The different codings prevent the mating of differently coded male and female connectors.
NOTE M8 is the dimension of the thread of the screw locking mechanism of these circular connectors.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050-581, International Electrotechnical Vocabulary (IEV) - Part 581: Electromechanical
components for electronic equipment
IEC 60068-1, Environmental testing - Part 1: General and guidance
IEC 60352-2, Solderless connections - Part 2: Crimped connections - General requirements,
test methods and practical guidance
IEC 60352-3, Solderless connections - Part 3: Accessible insulation displacement (ID)
connections - General requirements, test methods and practical guidance
IEC 60352-4, Solderless connections - Part 4: Non-accessible insulation displacement (ID)
connections - General requirements, test methods and practical guidance
IEC 60352-5, Solderless connections - Part 5: Press-in connections - General requirements,
test methods and practical guidance
IEC 60352-6, Solderless connections - Part 6: Insulation piercing connections - General
requirements, test methods and practical guidance
IEC 60352-7, Solderless connections - Part 7: Spring clamp connections - General
requirements, test methods and practical guidance
IEC 60352-9, Solderless connections - Part 9: Ultrasonically welded connections - General
requirements, test methods and practical guidance
IEC 60512 (all parts), Connectors for electrical and electronic equipment – Tests and
measurements
IEC 60512-1, Connectors for electrical and electronic equipment - Tests and measurements -
Part 1: General specification
IEC 60512-1-2, Connectors for electronic equipment - Tests and measurements - Part 1-2:
General examination - Test 1b: Examination of dimension and mass
IEC 61076-2-104:2026 © IEC 2026
IEC 60512-2-1, Connectors for electronic equipment - Tests and measurements - Part 2-1:
Electrical continuity and contact resistance tests - Test 2a: Contact resistance - Millivolt level
method
IEC 60512-3-1, Connectors for electronic equipment - Tests and measurements - Part 3-1:
Insulation tests - Test 3a: Insulation resistance
IEC 60512-4-1, Connectors for electronic equipment - Tests and measurements - Part 4-1:
Voltage stress tests - Test 4a: Voltage proof
IEC 60512-6-3, Connectors for electronic equipment - Tests and measurements - Part 6-3:
Dynamic stress tests - Test 6c: Shock
IEC 60512-6-4, Connectors for electronic equipment - Tests and measurements - Part 6-4:
Dynamic stress tests - Test 6d: Vibration (sinusoidal)
IEC 60512-9-1, Connectors for electronic equipment - Tests and measurements - Part 9-1:
Endurance tests - Test 9a: Mechanical operation
IEC 60512-13-2, Connectors for electronic equipment - Tests and measurements - Part 13-2:
Mechanical operation tests - Test 13b: Insertion and withdrawal forces
IEC 60512-13-5, Connectors for electronic equipment - Tests and measurements - Part 13-5:
Mechanical operation tests - Test 13e: Polarizing and keying method
IEC 60529:1989 + AMD1:1999 + AMD2:2013, Degrees of protection provided by enclosures
(IP code)
IEC 60664-1:2020, Insulation coordination for equipment within low-voltage supply systems -
Part 1: Principles, requirements and tests
IEC 60999-1, Connecting devices - Electrical copper conductors - Safety requirements for
screw-type and screwless-type clamping units - Part 1: General requirements and particular
2 2
requirements for clamping units for conductors from 0,2 mm up to 35 mm (included)
IEC 61076-1, Connectors for electronic equipment - Product requirements - Part 1: Generic
specification
IEC 61984:2008, Connectors - Safety requirements and tests
IEC 62197-1, Connectors for electronic equipment - Quality assessment requirements - Part 1:
Generic specification
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-581,
IEC 61076-1, IEC 60512-1 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
– IEC Electropedia: available at https://www.electropedia.org/
– ISO Online browsing platform: available at https://www.iso.org/obp
IEC 61076-2-104:2026 © IEC 2026
3.1
orientation
circular mounting position of the connector in relation to the polarization of the mating interface
4 Technical information
4.1 Recommended method of termination for connectors
The contact termination for rewirable connectors shall in accordance with the IEC 60352 series
or IEC 60999-1, as applicable, or shall be by soldering.
4.2 Connector coding, number of contacts, ratings and characteristics
Table 1 provides the coding of these connectors as a function of their style, number of contacts,
rated voltage and rated current.
Table 1 – Ratings of connectors
Coding Style Number of contacts Rated voltage Rated current
AC or DC A
3-way 3 50 V AC / 60 V DC 4
4-way 4 50 V AC / 60 V DC 4
A
6-way 6 32 V 1,5
8-way 8 32 V 1,5
B 5-way 5 32 V 3
C 12-way 12 32 V 1
NOTE The rated current refers to the interface. It refers to the maximum condu
...