ISO 3911:2021

FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 3911
ISO/TC 22/SC 33
Wheels and rims for pneumatic
Secretariat: DIN
tyres — Vocabulary, designation and
Voting begins on:
2021­03­19 marking
Voting terminates on:
Roues et jantes pour pneumatiques — Vocabulaire, désignation et
2021­05­14
marquage
RECIPIENTS OF THIS DRAFT ARE INVITED TO
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OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO­
ISO/FDIS 3911:2021(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN­
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2021

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ISO/FDIS 3911:2021(E)

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© ISO 2021
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ii © ISO 2021 – All rights reserved

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ISO/FDIS 3911:2021(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Wheel/rim size designation .15
4.1 Designation .15
4.2 Rim size/Contour types .16
5 Marking specifications .17
5.1 Marking of disc wheels and demountable rims .17
5.2 Marking of rings .17
5.3 Divided wheels .17
5.4 Height/legibility .17
5.5 Location/visibility .17
5.6 Additional markings .17
5.7 Offset, inset and outset marking .17
Bibliography .19
© ISO 2021 – All rights reserved iii

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ISO/FDIS 3911:2021(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non­governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the
World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www .iso .org/
iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 22, Road vehicles, Subcommittee SC 33,
Vehicle dynamics and chassis components.
This fourth edition cancels and replaces the third edition (ISO 3911:2004), which has been technically
revised.
The main changes compared to the previous edition are as follows:
— 3.8.1, optional bead seat profiles has been added;
— contre­pente (CP) hump in Figure 10 has been omitted;
— definition for five-piece rims have been amended to include 6-, 7-, 8- and 9-piece rims;
— 4,0 and 5,0 wheel designation and marking have been added, and annexes have been deleted;
— manually adjustable wheel graphic in Figure 8 has been made common with power adjustable
graphic.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
iv © ISO 2021 – All rights reserved

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FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 3911:2021(E)
Wheels and rims for pneumatic tyres — Vocabulary,
designation and marking
1 Scope
This document presents a vocabulary of terms related to, and systems for the designation and marking
of, wheels and rims intended for use with pneumatic tyres. The intention is to define fundamental
wheel and rim terms rather than provide a comprehensive tabulation of all wheel design features. Also
specified are the content, location and minimum size of the wheel and rim marking, with the purpose of
establishing, on a worldwide basis, a uniform identification system for wheels and rims.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
wheel
rotating load-carrying member between the tyre and the axle, usually consisting of two major parts,
the rim and the wheel disc, which may be integral, permanently attached or detachable
Note 1 to entry: See Figures 1 to 8.
3.2 wheel components
3.2.1
rim
part of the wheel (3.1) on which the tyre is mounted and supported
3.2.2
disc
wheel disc
part of the wheel (3.1) which is the supporting member between the axle and the rim
3.2.3
single wheel
wheel (3.1) which supports one tyre on one end of an axle
3.2.4
inset wheel
wheel (3.1) so constructed that the rim centreplane is located inboard of the attachment face of the disc
Note 1 to entry: See Figure 1 a).
Note 2 to entry: Inset is the distance from the attachment face of the disc to the rim centreplane.
© ISO 2021 – All rights reserved 1

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ISO/FDIS 3911:2021(E)

3.2.5
zeroset wheel
wheel (3.1) so constructed that the rim centreplane is coincident with the attachment face of the disc
Note 1 to entry: See Figure 1 b).
3.2.6
outset wheel
wheel (3.1) so constructed that the centreplane of the rim is located outboard of the attachment face of
the disc
Note 1 to entry: See Figure 1 c).
Note 2 to entry: Outset is the distance from the attachment face of the disc to the centreplane of the rim.
Note 3 to entry: Track, the distance between the centreplanes of the tyres on an axle, increases as the outset of
the wheels is increased.
a)  Inset wheel b)  Zeroset wheel c)  Outset wheel
Key
1 rim centreplane 7 attachment face diameter of wheel
2 disc 8 attachment face
3 nut seat 9 inset
4 bolt hole 10 rim
5 pitch circle diameter of bolt holes 11 zeroset
6 centre hole diameter 12 outset
Figure 1 — Passenger car and light commercial vehicle disc wheels — Nomenclature
3.2.7
dual wheel
wheel (3.1) with sufficient inset and configuration so that two such wheels, when assembled with each
other, support two tyres on one end of an axle
Note 1 to entry: See Figure 2.
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ISO/FDIS 3911:2021(E)

a)  Single application b)  Dual application
Key
1 rim centreplane 8 centre hole diameter
2 disc 9 attachment face
3 inset 10 attachment face diameter of wheel
4 external face of disc 11 rim
5 nut seat 12 dual spacing
6 bolt hole 13 offset
7 pitch circle diameter of bolt holes
Figure 2 — Commercial vehicle disc wheels — Nomenclature
3.2.8
dual spacing
distance between the centreplanes of the rims to provide the required clearance between the tyres
Note 1 to entry: See Figures 2, 5 and 6.
3.3 Wheel types
3.3.1
disc wheel
permanent combination of a rim and wheel disc
Note 1 to entry: See Figures 1 and 2.
3.3.2
divided wheel
wheel (3.1) so constructed that its two main parts, the rim portions of which might or might not be the
same in width, when securely fastened together with clamping bolts or equivalent mechanical means,
combine to form a rim having two fixed fl
...