2 Normative references

3 Terms and definitions

4 Wheel/rim size designation

4.1 Designation

4.2 Rim size/Contour types

5 Marking specifications

5.1 Marking of disc wheels and demountable rims

5.2 Marking of rings

5.3 Divided wheels

5.4 Height/legibility

5.5 Location/visibility

5.6 Additional markings

5.7 Offset, inset and outset marking

Bibliography

30mm

20mm

15mm

10mm

17mm

ISO 3911:2021(en)

	International Standard ISO 3911
Wheels and rims for pneumatic tyres — Vocabulary, designation and marking Roues et jantes pour pneumatiques — Vocabulaire, désignation et marquage Reference number ISO 3911:2021(en)	Fourth edition 2021-06 © ISO 2021

30mm

20mm

15mm

10mm

17mm

ISO 3911:2021(en)

All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of the requester.

ISO copyright office

CP 401 • Ch. de Blandonnet 8

CH-1214 Vernier, Geneva

Tel. + 41 22 749 01 11

E-mail copyright@iso.org

Website www.iso.org

Published in Switzerland

30mm

20mm

15mm

10mm

17mm

ISO 3911:2021(en)

ContentsPage

Foreword

1 Scope

2 Normative references

3 Terms and definitions

4 Wheel/rim size designation

4.1 Designation

4.2 Rim size/Contour types

5 Marking specifications

5.1 Marking of disc wheels and demountable rims

5.2 Marking of rings

5.3 Divided wheels

5.4 Height/legibility

5.5 Location/visibility

5.6 Additional markings

5.7 Offset, inset and outset marking

Bibliography

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 non-governmental, 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;

—

contre-pente (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.

30mm

20mm

15mm

10mm

17mm

ISO 3911:2021(en)

International StandardISO 3911:2021(en)

Wheels and rims for pneumatic tyres — Vocabulary, designation and marking

1Scope

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.

2Normative references

There are no normative references in this document.

3Terms 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.

3.2wheel 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.

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.

Figure 1 — Passenger car and light commercial vehicle disc wheels — Nomenclature


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

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.

Figure 2 — Commercial vehicle disc wheels — Nomenclature


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	half dual spacing
7	pitch circle diameter of bolt holes

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.

3.3Wheel 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 flanges

Note 1 to entry: See Figure 3.

Figure 3 — Divided wheel — Nomenclature

Key

1	rim centreplane
2	fixed flanges
3	clamping bolts or equivalent mechanical means
4	outset
5	attachment face

3.3.3

wire wheel

wheel (3.1) so constructed that its rim is joined to the centre member (shell) by a series of wire spokes

Note 1 to entry: See Figure 4.

Figure 4 — Wire wheels — Nomenclature


a) Conventional mounting type	b) Centre mounting type

Key

1	rim centreplane	5	inset
2	rim	6	cone seat for retaining nut
3	wire spokes	7	spline
4	centre member (shell)	8	hub seat reference plane

3.4Wheels with demountable rims

3.4.1

wheel with 28° mounting bevel

wheel (3.1) so constructed that one or two demountable rims are clamped to the cast wheel body, which also serves as the hub support for the brake drum or disc brake rotor

Note 1 to entry: Figure 5.

Figure 5 — Wheels with 28° mounting bevel — Nomenclature


a) Single	b) Dual

Key

1	rim centreplane	6	inner bearing cup shoulder (reference plane)
2	rim base offset	7	outset
3	wheel bevel offset	8	dual spacing
4	clamp	9	spacer band width
5	cast wheel body	10	rim bevel location

3.4.2

wheel with 18° [15°] mounting bevel

wheel (3.1) so constructed that one or two demountable rims are clamped to an 18° [15°] mounting bevel on the cast wheel body

Note 1 to entry: See Figure 6.

Figure 6 — Wheels with 18° [15°] mounting bevel — Nomenclature


a) Single	b) Dual

Key

1	rim centreplane	6	cast wheel body
2	wheel bevel offset	7	clamp
3	rim base offset	8	spacer band width
4	inset	9	dual spacing
5	inner bearing cup shoulder (reference plane)

3.5Wheels with more than one mounting option

3.5.1

reversible wheel

wheel (3.1) so constructed that its disc can be mounted on either face to provide inset (narrow track) or outset (wide track)

Note 1 to entry: See Figure 7.

Figure 7 — Reversible wheel

Key

1	rim centreplane
2	disc
3	attachment face
4	inset
5	rim
6	outset

3.6Wheels with adjustable rims

3.6.1

adjustable wheel

wheel (3.1) so constructed that the rim can be repositioned axially relative to the wheel disc

Note 1 to entry: Repositioning adjustments can be made manually or by power of the vehicle

Note 2 to entry: The power adjustable is a construction that can adjust the thread easily by loosening the clamp bolt without dismounting the rim from the disc, and by rotating the rim relatively to the wheel disc along the rail.

Note 3 to entry: See Figure 8 a) or b), respectively.

Note 4 to entry:

Figure 8 — Adjustable wheel

a) Manually adjustable

b) Power adjustable

Key

1	rim centreplane	5	rim
2	total adjustment with wheel reversed	6	total adjustment without wheel reversed
3	disc	7	rails
4	bracket	8	clamp

3.7Rim nomenclature

3.7.1

flange

part of the rim which provides lateral support to the tyre

Note 1 to entry: See Figure 9, a, b, g, r1, r2, r3.

3.7.2

bead seat

part of the rim which provides radial support to the tyre

Note 1 to entry: See Figure 9, D, p, r3, β.

3.7.3

well

part of the rim so located with sufficient depth and width to enable the tyre beads to be mounted and demounted over the mounting side rim flange or bead seat taper

Note 1 to entry: See Figure 9, H, l, m, r4, r5, α.

3.7.4

valve aperture

valve hole

hole or slot in the rim which accommodates the valve for tyre inflation

Note 1 to entry: See Figure 9, d and f.

3.7.5

gutter

groove in the rim base in which rim parts such as a spring lock ring or a detachable spring flange fit and are retained by the gutter tip

Note 1 to entry: See Figure 9, keys 2 and 3.

Figure 9 — Rim tyre side profiles — Nomenclature

Key

a	specified rim width	r2	flange radius
b	flange width	r3	bead seat radius
c	flange radius location	r4	well top radius — tyre mounting side
D	specified rim diameter	r5	well bottom radius
d	valve aperture	r6	flange edge radius
f	valve aperture location (for information only)	r7	flange radius at balance weight side
g	flange height	r8	well top radius — non tyre mounting side
H	well depth	α	side wall angle of well
l	well width	β	bead seat angle
m	well position	1	rim centreplane
p	bead seat width	2	gutter
r1	flange compound radius	3	gutter tip

Note 2 to entryFor ledge depth, h, see Figures 10 and 11.

Note 3 to entryFor multi-piece rims, the valve aperture location, f, may be measured from a fixed flange or inside edge of the gutter groove.

3.8Rim types

3.8.1

optional bead seat profiles

rim hump or special ledge geometries

Note 1 to entry: See Figure 10

Figure 10 — Optional bead seat profiles


a) Round hump (RH)	b) Special ledge (SL)		c) Flat hump (FH)

d) Combination hump (CH)		e) Double hump (H2)

Key

h	ledge depth

3.8.2

one‑piece rim

drop-centre rim

rim which is of one-piece construction and incorporates a well

Note 1 to entry: See Figure 11.

Figure 11 — One-piece (drop-centre) rims — Nomenclature


a) Passenger car 5° DC	b) Agricultural 5° DC (with secondary well in dashed line)

c) Commercial vehicle 15° DC	d) Mobile home and low bed trailer 15° DC demountable

Key

h	ledge depth

3.8.3

two-piece rim

rim of construction with two pieces

Note 1 to entry: See Figure 12.

Figure 12 — Two-piece rims — Nomenclature

Key

1	detachable spring flange	3	rim base
2	gutter portion	4	rim base (semi-drop-centre)

3.8.4

three-piece rim

rim of construction with three pieces

Note 1 to entry: See Figure 13.

Figure 13 — Three-piece rims — Nomenclature

Key

1	detachable endless flange	6	3 x 120° segment rim
2	spring lock ring	7	18° [15°] bevel
3	gutter portion	8	detachable endless flange with tapered bead seat
4	rim base	9	spring lock ring
5	rim base (semi-drop-centre)

3.8.5

four-piece rim

rim of construction with four pieces

Note 1 to entry: See Figure 14.

Figure 14 — Four-piece rims — Nomenclature

Key

1	detachable endless flange
2	gutter portion
3	spring lock ring
4	rim base
5	spring tapered bead seat ring

3.8.6

five- or more piece rims

rim of construction with five or more pieces such that the detachable flange may consist of separate types and pieces for a total of 5, 6, 7, or 8 pieces

Note 1 to entry: See Figure 15.

Figure 15 — Five- or more piece rims — Nomenclature


a) 5-piece rim	b) 6-piece rim (7-piece rima)

c) 7-piece rim (7, 8, 9-piece rima)

Key

1	detachable endless flange
2	spring lock ring
3	gutter portion
4	groove for O-ring seal for tubeless type applications
5	rim base
6	detachable endless tapered bead seat ring
a	Lock ring may be two-part lock ring.

30mm

20mm

15mm

10mm

17mm

ISO 3911:2021(en)

Bibliography

[1]		ISO 4000-2, Passenger car tyres and rims — Part 2: Rims
[2]		ISO 4209-2, Truck and bus tyres and rims (metric series) — Part 2: Rims
[3]		ISO 18804, Tyres (ply rating marked series) and rims for agricultural tractors and machines — Part 3: Rims

30mm

20mm

15mm

10mm

17mm


ICS 01.040.43; 43.040.50 Price based on 19 pages © ISO 2021All rights reserved	iso.org