oSIST prEN IEC 60297-3-103:2026

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

Mehanske konstrukcije elektronske opreme - Mere mehanskih konstrukcij v seriji 482,6 mm (19 in) - 3-103. del: Kodirni in poravnalni trn

General Information

• Status: Not Published
• Public Enquiry End Date: 31-Jan-2026
• ICS: 31.240 - Mechanical structures for electronic equipment
• Technical Committee: I11 - Imaginarni 11
• Current Stage: 4020 - Public enquire (PE) (Adopted Project)
• Start Date: 18-Nov-2025
• Due Date: 07-Apr-2026
• Completion Date: 26-Jan-2026
• Ref Project: prEN IEC 60297-3-103:2025 - Mechanical structures for electronic equipment - Dimensions of mechanical structures of the 482,6 mm (19 in) series - Part 3-103: Keying and alignment pin

Relations

• Revises: SIST EN 60297-3-103:2005 - 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

oSIST prEN IEC 60297-3-103:2026 specifies the critical mechanical dimensions and interface features of the 482,6 mm (19 in) series for electronic equipment - with a focus on keying and alignment pins. Developed by SIST in line with IEC guidance, this standard ensures reliable interoperability, safety, and compatibility for modular electronic systems built around the widely used 19-inch subrack format. By standardizing the configurations of keying and alignment features, it helps manufacturers, integrators, and end-users achieve consistent assembly, error-proof installation, and enhanced mechanical stability in electronic hardware installations.

Standardized keying and alignment components are foundational in preventing damage, misconfiguration, and operational failures in high-density electronic racks. This part of IEC 60297 defines those physical attributes that maximize system reliability for telecom, IT, industrial, and instrumentation applications.

Key Topics

• Keying Devices and Positioning: Outlines the methods for implementing mechanical keying mechanisms in subracks and plug-in units to prevent incorrect module insertion.
• Alignment Pin Geometry: Details the arrangements and dimensions of alignment pins for accurate positioning and robust mechanical coupling.
• Interface Dimensions: Specifies interface details between subracks and plug-in modules, including snap-in features and chamber inspection points.
• Programming of Key Positions: Provides a system for uniquely identifying keying requirements, supporting modularity and scalability in subrack layouts.
• Inspection and Verification: Shares guidance for ensuring correct installation by means of inspection dimensions and mirror image conventions for rear mounting.
• Compatibility: Designed for use with IEC 60297-3-101 and IEC 60297-3-102, supporting 3U, 6U, and 9U subrack heights and associated plug-in unit types.
• Printed Board Offset Arrangement: Clarifies arrangements when a 2.54 mm offset for the printed board reference plane is required, ensuring alignment consistency.

Applications

The specifications presented in oSIST prEN IEC 60297-3-103:2026 are essential for:

• Telecommunications Equipment: Guaranteeing securely keyed and aligned modules in central office, base station, and access network racks.
• IT/Data Center Infrastructure: Supporting critical server, storage, and networking components in modular rack systems.
• Industrial Control Systems: Ensuring safe and reliable plug-in unit installation in process control, automation, and rugged industrial electronics.
• Test and Measurement: Standardizing system interfaces for instrumentation adopted by vendors participating in open hardware ecosystems.
• Maintenance and Retrofits: Allowing for tool-less, error-proof replacement and upgrade of modules, reducing downtime and service costs.

By using this standard, organizations minimize the risk of equipment misalignment and damage, simplify configuration management, and streamline global equipment supply chains.

Related Standards

For comprehensive mechanical compatibility and further system specifications, refer to:

• 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: Dimensions of mechanical structures of the 482,6 mm (19 in) series - Injector/extractor handle
• IEC 60917-1:2019: Modular order for the development of mechanical structures for electrical and electronic equipment - Generic standard
• IEC TR 60297-3-1:2023: General overview and context of modular 19-inch systems

These standards form the basis of a robust and flexible infrastructure for electronic equipment based on the 19-inch rack system, promoting safe, efficient, and interoperable solutions worldwide.

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By adhering to oSIST prEN IEC 60297-3-103:2026, stakeholders in electronics design and manufacturing enhance equipment reliability, ensure global compatibility, and facilitate long-term system maintenance for critical electronic assemblies.

Standards Content (Sample)

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
NOTE FROM TC/SC OFFICERS:
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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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