FprEN IEC 60297-3-103:2026

• Status: Not Published
• Publication Date: 20-Dec-2026
• ICS: 31.240 - Mechanical structures for electronic equipment
• Technical Committee: CLC/SR 48D - Mechanical structures for electronic equipment
• Current Stage: 5020 - Vote circulated - Formal Approval
• Start Date: 07-Aug-2026
• Completion Date: 07-Aug-2026
• Ref Project: oSIST prEN IEC 60297-3-103:2026 - Mechanical structures for electronic equipment - Dimensions of mechanical structures of the 482,6 mm (19 in) series - Part 3-103: Keying and alignment pin

• Revises: EN 60297-3-103:2004 - Mechanical structures for electronic equipment - Dimensions of mechanical structures of the 482,6 mm (19 in) series - Part 3-103: Keying and alignment pin
• Effective Date: 22-Jul-2025

Overview

FprEN IEC 60297-3-103:2026 defines the interface dimensions for keying and alignment pins used in mechanical structures for electrical and electronic equipment within the 482.6 mm (19-inch) series. It is part of the IEC 60297 family of standards, which establishes specifications for 19-inch subrack systems widely adopted in industrial, telecom, and electronic equipment enclosures.

This standard focuses on ensuring secure and accurate insertion of plug-in units into subracks by preventing misconnection and providing alignment, which helps maintain system reliability, interoperability, and mechanical integrity. It applies alongside related parts such as IEC 60297-3-101 and IEC 60297-3-102 covering subracks, plug-in units, and associated features.

Key Topics

• Keying Mechanisms for Plug-in Units

  • Specifies snap-in keying devices for plug-in modules and the subrack guide rails
  • Prevents misplacement and misconnection of plug-in cards and boards
  • Recommends key placement for subracks of different heights (3U, 6U, 9U)
  • Supports retrofit and interchangeability

• Alignment and Electrical Contact Points

  • Addresses alignment pin receptacle positioning in the subrack guide rail
  • Enables precise alignment to ensure correct positioning and electrical contact
  • Supports use of earth contact for grounding where applicable

• Standardized Dimensions

  • Unifies dimensions for keying and alignment pins across equipment using the 19-inch format
  • References interface dimensions in IEC 60297-3-101 for full compatibility

• Modular System Compatibility

  • Maintains consistent design language across IEC 60297-3-xxx series
  • Supports modular assembly, upgrades, and systems integration

Applications

The standard provides value in a range of practical contexts focused on the 19-inch rack system:

• Industrial Automation

  • Ensures safe and reliable deployment of control and I/O modules in standardized racks

• Telecommunications Infrastructure

  • Provides robust mechanical and electrical interconnect integrity for switches, patch panels, and network devices

• Data Centers & IT Equipment

  • Facilitates secure insertion and replacement of servers, storage units, and network gear

• Test and Measurement Equipment

  • Allows consistent installation and servicing of instrumentation plug-ins in laboratory racks

• OEM Design and Manufacturing

  • Supports system integrators and manufacturers in designing products with standardized form factors for maximum interoperability and ease of maintenance

By adopting the keying and alignment pin specifications in FprEN IEC 60297-3-103:2026, organizations can significantly reduce the risk of installation errors, improve equipment lifespan, and support safe, straightforward maintenance routines.

Related Standards

• IEC 60297-3-101 – Dimensions of mechanical structures of the 482.6 mm (19 in) series: subracks and associated plug-in units
• IEC 60297-3-102 – Injector/extractor handle requirements for the 19-inch series
• IEC 60917-1 – Modular order for the development of mechanical structures for electrical and electronic equipment
• IEC TR 60297-3-1:2023 – Details extended specifications for 19-inch subrack systems

For optimal results, FprEN IEC 60297-3-103:2026 should be implemented together with these complementary standards to ensure comprehensive compliance in 19-inch rack mechanical design and integration projects.

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Keywords: IEC 60297, 19-inch rack, mechanical structure, electronic equipment, keying pin, alignment pin, subrack, plug-in unit, standard dimensions, interoperability, equipment design, rack mount systems

SLOVENSKI STANDARD
01-januar-2026
Mehanske konstrukcije elektronske opreme - Mere mehanskih konstrukcij v seriji
482,6 mm (19 in) - 3-103. del: Kodirni in poravnalni trn
Mechanical structures for electronic equipment - Dimensions of mechanical structures of
the 482,6 mm (19 in) series - Part 3-103: Keying and alignment pin
Bauweisen für elektronische Einrichtungen - Maße der 482,6-mm-(19-in-)Bauweise - Teil
3-103: Kodierung und Führungsstift
Structures mécaniques pour équipements électroniques - Dimensions des structures
mécaniques de la série 482,6 mm (19 pouces) - Partie 3-103: Codage et broche
d'alignement
Ta slovenski standard je istoveten z: prEN IEC 60297-3-103:2025
ICS:
31.240 Mehanske konstrukcije za Mechanical structures for
elektronsko opremo electronic equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

48D/795/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 60297-3-103 ED2
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2025-11-14 2026-02-06
SUPERSEDES DOCUMENTS:
48D/791/RR
IEC SC 48D : MECHANICAL STRUCTURES FOR ELECTRICAL AND ELECTRONIC EQUIPMENT
SECRETARIAT: SECRETARY:
Germany Mr Arno Bergmann
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):

SC 48B
ASPECTS CONCERNED:
Safety
SUBMITTED FOR CENELEC PARALLEL VOTING NOT SUBMITTED FOR CENELEC PARALLEL VOTING
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TITLE:
Mechanical structures for electronic equipment - Dimensions of mechanical structures of the
482,6 mm (19 in) series - Part 3-103: Keying and alignment pin

PROPOSED STABILITY DATE: 2029
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IEC 60297-3-103 ED2 © IEC 2025

Link to Committee Draft for Vote (CDV) online document:
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IEC 60297-3-103 ED2 © IEC 2025

CONTENTS
CONTENTS . 1
FOREWORD . 3
INTRODUCTION . 5
1 Scope and object . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Arrangement overview: Keying of plug-in units in a subrack. 6
4.1 General . 6
4.2 Subrack interface dimensions for keying . 8
4.3 Plug-in unit keying interface dimensions . 8
4.4 Key dimensions . 8
4.5 Programming of keys . 9
4.6 Keying chamber inspection dimensions . 10
5 Arrangement overview: alignment and/or electrical contact of a plug-in unit to a
subrack . 11
5.1 General . 11
5.2 Alignment and/or electrical contact receptacle in the subrack guide rail for
printed board type plug-in units (width dimension ≥ 4 × 5,08 mm) . 12
5.3 Alignment and/or electrical contact interface inspection dimensions . 13
6 Arrangement overview: Subrack guide rail and printed board, 2,54 mm offset of
the printed board reference plane . 13
6.1 General . 13
6.2 Dimensions of the subrack guide rail with 2,54 mm offset of the printed
board reference plane . 15
6.3 Reference plane for printed boards with 2,54 mm offset position . 16
7 Dimensions used in the figures . 16
Bibliography . 17

Figure 1 – Conventional 19-inch subrack system mechanical structure . 5
Figure 2 – Keying of plug-in unit in a subrack . 7
Figure 3 – Subrack interface dimensions for keying . 8
Figure 4 – Plug-in unit keying interface dimensions . 8
Figure 5 – Key dimensions . 9
Figure 6 – Programming of keys . 10
Figure 7 – Front and/or rear subrack and plug-in unit keying chamber inspection
dimensions . 10
Figure 8 – Alignment and/or electrical contact of a plug-in unit to a subrack . 11
Figure 9 – Alignment and/or electrical contact receptacle position in the subrack . 12
Figure 10 – Alignment and/or electrical contact interface inspection dimensions . 13
Figure 11 – Subrack guide rail and printed board, 2,54 mm offset of the printed board
reference plane . 14
Figure 12 – Dimensions of the subrack guide rail with 2,54 mm offset of the printed
board reference plane . 15
Figure 13 – Reference plane for printed boards with 2,54 mm offset position . 16

IEC 60297-3-103 ED2 © IEC 2025

Table 1 – Subrack and plug-in unit keying chamber inspection dimensions . 10

IEC 60297-3-103 ED2 © IEC 2025

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Mechanical structures for electronic equipment - Dimensions of
mechanical structures of the 482,6 mm (19 in) series -
Part 3-103: Keying and alignment pin

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