SIST EN IEC 60072-3:2026

• Abstract:

  IEC 60072-3: 2026 applies to small built-in motors with a pitch circle diameter of the flange between 10 mm and 50 mm. It provides a table with fixing dimensions, shaft extension dimensions and their tolerances.; This second edition cancels and replaces the firstedition published in 1994. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition:; a) clarification of the scope.

• Status: Published
• Publication Date: 26-Aug-2026
• ICS: 29.160.01 - Rotating machinery in general
• ICS: 29.160.30 - Motors
• Technical Committee: ERS - Rotating machinery
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 11-Nov-2025
• Due Date: 16-Jan-2026
• Completion Date: 27-Aug-2026
• Ref Project: EN IEC 60072-3:2026 - Rotating electrical machines - Dimensions and output series - Part 3: Small built-in motors - Flange numbers BF10 to BF50

• Referred By: SIST-TS CLC IEC/TS 60034-31:2024 - Rotating electrical machines - Part 31: Selection of energye-fficient motors including variable speed applications - Application guidelines (IEC/TS 60034-31:2021)
• Effective Date: 24-Mar-2026

SIST EN IEC 60072-3:2026 is a CENELEC European Standard based on IEC 60072-3:2026 for rotating electrical machines. It specifies fixing dimensions, shaft extension dimensions, and the related tolerances for small built-in motors with flange pitch circle diameters from 10 mm to 50 mm.

What does SIST EN IEC 60072-3:2026 specify?

SIST EN IEC 60072-3:2026 applies to small built-in motors with a pitch circle diameter of the flange between 10 mm and 50 mm. For users, that means the document is about the mounting interface and shaft end dimensions that must fit together in practice.

The document is organized into Scope, Normative references, Terms and definitions, Symbols, and Fixing dimensions and tolerances, followed by a bibliography. Figure 1 gives the dimensional sketch, and Table 1 provides the flange-to-shaft dimension relationships and tolerances.

What are the key requirements of SIST EN IEC 60072-3:2026?

SIST EN IEC 60072-3:2026 focuses on the geometry needed to mount and connect small built-in motors consistently. The main practical result is a standard set of dimensions and tolerance classes that help designers, manufacturers, and inspectors work to the same interface.

Symbols and dimensional sketch

Clause 4 defines the letter symbols used in the dimensional sketches. The symbols marked with an asterisk are mandatory dimensions, so they are the ones that need to be treated as essential in design drawings and checks.

• D - diameter of the shaft extension at the D-end.
• E - length of the shaft extension from the shoulder at the D-end.
• M - pitch circle diameter of the fixing holes.
• N - diameter of the spigot.
• S - diameter of the fixing holes in the mounting flange or nominal diameter of thread.
• T - depth of the spigot.

In practice, these symbols tell a drawing office or inspection team exactly which features are being controlled on the motor interface.

Fixing dimensions and tolerances

Clause 5 and Table 1 link flange numbers BF10 to BF50 with the fixing dimensions and shaft extension dimensions. The table covers the key interface features - fixing-hole size, pitch circle diameter, spigot diameter and depth, shaft diameter, shaft extension length, and the stated tolerances.

That matters when selecting a motor or checking compatibility with a housing, bracket, or driven component. If the flange number is known, Table 1 gives the corresponding dimensional set to manufacture or verify against.

Tolerances and preferred values

The tolerances in Table 1 use standard classes such as h6 and js6, and the note to the table ties these to ISO 286-2. In practice, this means the document is not only giving nominal sizes but also the tolerance system needed to machine and inspect the parts correctly.

The table also notes that values in brackets should be avoided wherever possible. For users, this is a design preference that helps steer selection toward the preferred dimensional choices.

Special notes on the flange arrangement

The document states that the arrangement of the tapped holes is independent of the position of the axis of the poles and brush axes. In practical terms, the flange-hole layout is treated separately from the internal electromagnetic orientation of the machine.

The table also allows M 1,6 for flange BF16 in short machines. That gives designers a specific permitted alternative when they are working with that flange size.

What terms does SIST EN IEC 60072-3:2026 define?

SIST EN IEC 60072-3:2026 does not list terms and definitions, but clause 4 gives the key symbols used in the document. These symbols are the working vocabulary for the dimensions in Figure 1 and Table 1.

• D - shaft extension diameter at the D-end.
• E - shaft extension length measured from the D-end shoulder.
• M - pitch circle diameter of the fixing holes.
• N - spigot diameter.
• S - fixing-hole diameter in the flange, or nominal thread diameter.
• T - spigot depth.

Who uses SIST EN IEC 60072-3:2026?

SIST EN IEC 60072-3:2026 is used by motor manufacturers, mechanical designers, machine builders, quality control teams, and buyers who specify small built-in motors. They use it to make sure the flange, shaft, and fixing-hole interface matches the mating part.

It is also useful in inspection and receiving checks, because the document gives the dimensions and tolerance classes needed to verify conformance at the mounting interface.

What changed in SIST EN IEC 60072-3:2026 from the previous edition?

SIST EN IEC 60072-3:2026 is the second edition and it cancels and replaces the first edition published in 1994. The stated technical revision is a clarification of the scope.

Which standards are used with SIST EN IEC 60072-3:2026?

ISO 286-2 is used with SIST EN IEC 60072-3:2026 for the tolerance system. Clause 5 and the note to Table 1 rely on it for standard tolerance classes and limit deviations for holes and shafts.

What does the SIST EN IEC 60072-3:2026 document contain?

SIST EN IEC 60072-3:2026 is a short dimensional standard with five clauses, one figure, one table, and a bibliography. Figure 1 shows the dimensional sketches and identifies the symbols used for the flange and shaft features.

Table 1 is the core of the document: it correlates flange numbers BF10 to BF50 with fixing dimensions, shaft extension dimensions, and tolerances. The document is therefore mainly a design-and-inspection reference for matching small built-in motors to their mounting arrangements.

SLOVENSKI STANDARD
01-oktober-2026
Električni rotacijski stroji - Dimenzije in izhodne serije - 3. del: Majhni vgradni
motorji - Velikosti prirobnic od BF10 do BF50 (IEC 60072-3:2026)
Rotating electrical machines - Dimensions and output series - Part 3: Small built-in
motors - Flange numbers BF10 to BF50 (IEC 60072-3:2026)
Maße und Leistungsreihen für drehende elektrische Maschinen - Teil 3: Kleine
Einbaumotoren - Flanschgrößen BF10 bis BF50 (IEC 60072-3:2026)
Machines électriques tournantes - Dimensions et séries de puissances - Partie 3: Petits
moteurs incorporés - Désignation des brides BF10 à BF50 (IEC 60072-3:2026)
Ta slovenski standard je istoveten z: EN IEC 60072-3:2026
ICS:
29.160.30 Motorji Motors
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60072-3

NORME EUROPÉENNE
EUROPÄISCHE NORM March 2026
ICS 29.160.01
English Version
Rotating electrical machines - Dimensions and output series -
Part 3: Small built-in motors - Flange numbers BF10 to BF50
(IEC 60072-3:2026)
Machines électriques tournantes - Dimensions et séries de Maße und Leistungsreihen für drehende elektrische
puissances - Partie 3: Petits moteurs incorporés - Maschinen - Teil 3: Kleine Einbaumotoren - Flanschgrößen
Désignation des brides BF10 à BF50 BF10 bis BF50
(IEC 60072-3:2026) (IEC 60072-3:2026)
This European Standard was approved by CENELEC on 2026-03-13. 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 60072-3:2026 E

European foreword
The text of document 2/2280/FDIS, future edition 2 of IEC 60072-3, prepared by TC 2 "Rotating
machinery" was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as
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
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 60072-3:2026 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following note has to be added for the standard indicated:
ISO 286-2 NOTE Approved as EN ISO 286-2

IEC 60072-3 ®
Edition 2.0 2026-02
INTERNATIONAL
STANDARD
Rotating electrical machines - Dimensions and output series -
Part 3: Small built-in motors - Flange numbers BF10 to BF50
ICS 29.160.01  ISBN 978-2-8327-1041-8

IEC 60072-3:2026-02(en)
IEC 60072-3:2026 © IEC 2026
CONTENTS
FOREWORD . 2
1 Scope . 4
2 Normative references . 4
3 Terms and definitions . 4
4 Symbols . 4
4.1 Letter symbols for dimensions . 4
4.2 Dimensional sketches . 4
5 Fixing dimensions and tolerances . 5
Bibliography . 6

Figure 1 – Dimensional sketches . 4

Table 1 – Dimensions and tolerances for flanges and shafts . 5

IEC 60072-3:2026 © IEC 2026
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
Rotating electrical machines -
Dimensions and output series -
Part 3: Small built-in motors - Flange numbers BF10 to BF50

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
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