Geometrical product specifications (GPS) - Geometrical tolerancing - Maximum material requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR) (ISO 2692:2021)

Geometrische Produktspezifikation (GPS) - Geometrische Tolerierung - Maximum-Material-Bedingung (MMR), Minimum-Material-Bedingung (LMR) und Reziprozitätsbedingung (RPR) (ISO 2692:2021)

Dieses Dokument legt die Maximum-Material-Bedingung (MMR), die Minimum-Material-Bedingung (LMR) und die Reziprozitätsbedingung (RPR) fest. Diese Anforderungen können ausschließlich auf lineare Größenmaßelemente vom Typ zylindrisch oder zwei parallele gegenüberliegende Ebenen angewendet werden.
Diese Anforderungen dienen oftmals zur Steuerung bestimmter Funktionen von Werkstücken, bei denen eine Abhängigkeit von Größenmaß und Geometrie vorhanden ist, beispielsweise zur Erfüllung der Funktionen „Zusammenbau von Teilen“ (für die MMR) oder „Mindestwandstärke“ (für die LMR). Die MMR und die LMR können jedoch auch zur Erfüllung sonstiger funktionaler Konstruktionsanforderungen genutzt werden.

Spécification géométrique des produits (GPS) - Tolérancement géométrique - Exigence du maximum de matière (MMR), exigence du minimum de matière (LMR) et exigence de réciprocité (RPR) (ISO 2692:2021)

Specifikacija geometrijskih veličin izdelka (GPS) - Tolerance geometrijskih veličin - Zahteva po maksimalnem materialu, zahteva po minimalnem materialu in zahteva po usklajenosti materialov (ISO 2692:2021)

General Information

Status
Published
Public Enquiry End Date
31-Jul-2019
Publication Date
20-Jul-2021
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Jul-2021
Due Date
05-Sep-2021
Completion Date
21-Jul-2021

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SLOVENSKI STANDARD
SIST EN ISO 2692:2021
01-september-2021
Nadomešča:
SIST EN ISO 2692:2015

Specifikacija geometrijskih veličin izdelka (GPS) - Tolerance geometrijskih veličin -

Zahteva po maksimalnem materialu, zahteva po minimalnem materialu in zahteva
po usklajenosti materialov (ISO 2692:2021)

Geometrical product specifications (GPS) - Geometrical tolerancing - Maximum material

requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR)

(ISO 2692:2021)
Geometrische Produktspezifikation (GPS) - Geometrische Tolerierung - Maximum-
Material-Bedingung (MMR), Minimum-Material-Bedingung (LMR) und
Reziprozitätsbedingung (RPR) (ISO 2692:2021)

Spécification géométrique des produits (GPS) - Tolérancement géométrique - Exigence

du maximum de matière (MMR), exigence du minimum de matière (LMR) et exigence de
réciprocité (RPR) (ISO 2692:2021)
Ta slovenski standard je istoveten z: EN ISO 2692:2021
ICS:
01.100.20 Konstrukcijske risbe Mechanical engineering
drawings
17.040.40 Specifikacija geometrijskih Geometrical Product
veličin izdelka (GPS) Specification (GPS)
SIST EN ISO 2692:2021 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN ISO 2692:2021
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SIST EN ISO 2692:2021
EN ISO 2692
EUROPEAN STANDARD
NORME EUROPÉENNE
June 2021
EUROPÄISCHE NORM
ICS 01.100.20 Supersedes EN ISO 2692:2014
English Version
Geometrical product specifications (GPS) - Geometrical
tolerancing - Maximum material requirement (MMR), least
material requirement (LMR) and reciprocity requirement
(RPR) (ISO 2692:2021)

Spécification géométrique des produits (GPS) - Geometrische Produktspezifikation (GPS) -

Tolérancement géométrique - Exigence du maximum Geometrische Tolerierung - Maximum-Material-

de matière (MMR), exigence du minimum de matière Bedingung (MMR), Minimum-Material-Bedingung

(LMR) et exigence de réciprocité (RPR) (ISO (LMR) und Reziprozitätsbedingung (RPR) (ISO

2692:2021) 2692:2021)
This European Standard was approved by CEN on 1 June 2021.

CEN 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 CEN

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 CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 2692:2021 E

worldwide for CEN national Members.
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SIST EN ISO 2692:2021
EN ISO 2692:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 3

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SIST EN ISO 2692:2021
EN ISO 2692:2021 (E)
European foreword

This document (EN ISO 2692:2021) has been prepared by Technical Committee ISO/TC 213

"Dimensional and geometrical product specifications and verification" in collaboration with Technical

Committee CEN/TC 290 “Dimensional and geometrical product specification and verification” the

secretariat of which is held by AFNOR.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by December 2021, and conflicting national standards

shall be withdrawn at the latest by December 2021.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN ISO 2692:2014.

According to the CEN-CENELEC Internal Regulations, the national standards organizations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,

Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland,

Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of

North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the

United Kingdom.
Endorsement notice

The text of ISO 2692:2021 has been approved by CEN as EN ISO 2692:2021 without any modification.

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SIST EN ISO 2692:2021
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SIST EN ISO 2692:2021
INTERNATIONAL ISO
STANDARD 2692
Fourth edition
2021-06
Geometrical product specifications
(GPS) — Geometrical tolerancing
— Maximum material requirement
(MMR), least material requirement
(LMR) and reciprocity requirement
(RPR)
Spécification géométrique des produits (GPS) — Tolérancement
géométrique — Exigence du maximum de matière (MMR), exigence
du minimum de matière (LMR) et exigence de réciprocité (RPR)
Reference number
ISO 2692:2021(E)
ISO 2021
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SIST EN ISO 2692:2021
ISO 2692:2021(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2021

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
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2021 – All rights reserved
---------------------- Page: 8 ----------------------
SIST EN ISO 2692:2021
ISO 2692:2021(E)
Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Maximum material requirement (MMR) and least material requirement (LMR) ...........................5

4.1 General ........................................................................................................................................................................................................... 5

4.1.1 MMVS or LMVS specification ................................................................................................................................. 5

4.1.2 Indirect determination of MMVS or LMVS ................................................................................................. 5

4.1.3 Direct indication of MMVS or LMVS ................................................................................................................ 6

4.1.4 MMR or LMR applied to several toleranced features ....................................................................... 7

4.1.5 Simultaneous requirement ..................................................................................................................................... 7

4.1.6 MMR or LMR on a datum without MMR or LMR on the toleranced feature ................. 7

4.2 Maximum material requirement (MMR) .......................................................................................................................... 7

4.2.1 MMR for toleranced features with indirect determination of virtual size ..................... 7

4.2.2 MMR for related datum features with indirect determination of virtual size ............ 8

4.2.3 MMR for toleranced features with direct indication of virtual size ..................................10

4.2.4 MMR for related datum features with direct indication of virtual size .........................10

4.3 Least material requirement (LMR) ....................................................................................................................................11

4.3.1 LMR for toleranced features with indirect determination of virtual size ....................11

4.3.2 LMR for related datum features with indirect determination of virtual size ...........12

4.3.3 LMR for toleranced features with direct indication of virtual size ....................................13

4.3.4 LMR for related datum features with direct indication of virtual size ...........................14

5 Reciprocity requirement (RPR) .........................................................................................................................................................15

5.1 General ........................................................................................................................................................................................................15

5.2 Reciprocity requirement (RPR) and maximum material requirement (MMR) ............................15

5.3 Reciprocity requirement (RPR) and least material requirement (LMR) ...........................................15

Annex A (informative) Examples of tolerancing with , and .....................................................................................16

Annex B (informative) Former practice..........................................................................................................................................................48

Annex C (informative) Concept diagram ........................................................................................................................................................49

Annex D (informative) Use of symbols for geometrical characteristics with or .....................................51

Annex E (informative) Relation to the GPS matrix model............................................................................................................53

Bibliography .............................................................................................................................................................................................................................54

© ISO 2021 – All rights reserved iii
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SIST EN ISO 2692:2021
ISO 2692:2021(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 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 213, Dimensional and geometrical product

specifications and verification, in collaboration with the European Committee for Standardization (CEN)

Technical Committee CEN/TC 290, Dimensional and geometrical product specification and verification, in

accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).

This fourth edition cancels and replaces the third edition (ISO 2692:2014), which has been technically

revised.
The main changes to the previous edition are as follows:

— direct indication of maximum material or least material virtual size has been added (see 4.1.3);

— the use of SZ or CZ symbols has been added (see 4.1.4);
— the use of SIM symbol has been added (see 4.1.5).

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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SIST EN ISO 2692:2021
ISO 2692:2021(E)
Introduction
0.1 General

This document is a geometrical product specification (GPS) standard and is to be regarded as a general

GPS standard (see ISO 14638). It influences the chain links A, B and C of the chain of standards on size,

form, orientation and location.

The ISO/GPS matrix model given in ISO 14638 gives an overview of the ISO/GPS system of which this

document is a part. The fundamental rules of ISO/GPS given in ISO 8015 apply to this document and

the default decision rules given in ISO 14253-1 apply to specifications made in accordance with this

document, unless otherwise indicated.

For more detailed information on the relation of this document to the GPS matrix model, see Annex E.

This document deals with some frequently occurring workpiece functional cases in design and

tolerancing. The “maximum material requirement” (MMR) can cover, for example, “assemblability” and

the “least material requirement” (LMR) can cover, for example, “minimum wall thickness” of a part.

MMR and LMR requirements can accurately simulate the intended function of the workpiece by allowing

the combination of two independent requirements into one collective requirement or to directly define

maximum material virtual condition (MMVC) or least material virtual condition (LMVC) (see Annex C).

In some cases of both MMR and LMR, the “reciprocity requirement” (RPR) can be added.

NOTE 1 In GPS standards, threaded features are often considered as a type of cylindrical feature of size.

However, no rules are defined in this document for how to apply MMR, LMR and RPR to threaded features.

Consequently, application of the tools defined in this document for threaded features is risky.

NOTE 2 A geometrical tolerance value of 0 (0 or 0 ) can be used to avoid non-conformity of parts that can

be assembled, in the case of MMR, or have minimum wall thickness, in the case of LMR.

0.2 Information about MMR
The assembly of parts depends on the combined effect of:
a) the size (of one or more features of size), and

b) the geometrical deviation of the features and their derived features, such as the pattern of bolt

holes in two flanges and the bolts securing them.

The minimum assembly clearance occurs when each of the mating features of size is at its maximum

material size (MMS) (e.g. the largest bolt size and the smallest hole size) and when the geometrical

deviations (e.g. the form, orientation and location deviations) of the features of size and their derived

features (median line or median surface) are also fully consuming their tolerances. Assembly clearance

increases to a maximum when the sizes of the assembled features of size are furthest from their MMSs

(e.g. the smallest shaft size and the largest hole size) and when the geometrical deviations (e.g. the

form, orientation and location deviations) of the features of size and their derived features are zero.

It therefore follows that to manage the assemblability, the effect of the dimensional and geometrical

variation can be dealt with by a specification using the maximum material concept. This requirement is

indicated on the drawing by the symbol .

Furthermore, it can be useful to add to the datum indicator in the datum section when the datum is

a feature of linear size and the clearance between the datum and the counterpart is favourable to the

assembly of the part.
0.3 Information about LMR

The LMR is designed to control, for example, the minimum wall thickness, thereby preventing burst

(due to pressure in a tube), or the maximum width of a series of slots. To manage the material strength

function, the effect of the dimensional and geometrical variation can be dealt with by a specification

using the minimum material concept. This requirement is indicated on drawings by the symbol .

© ISO 2021 – All rights reserved v
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SIST EN ISO 2692:2021
ISO 2692:2021(E)
0.4 Information about RPR

The RPR is an additional modifier, which may be used together with the MMR or with the LMR in cases

where it is permitted – taking into account the function of the toleranced feature(s) – to enlarge the

size tolerance when the geometrical deviation on the actual workpiece does not take full advantage of,

respectively, the MMVC or the LMVC.
The RPR is indicated on drawings by the symbol .
0.5 General information about terminology and figures

The terminology and tolerancing concepts in this document have been updated to conform to GPS

terminology, notably that in ISO 286-1, ISO 14405-1, ISO 17450-1 and ISO 17450-3.

vi © ISO 2021 – All rights reserved
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SIST EN ISO 2692:2021
INTERNATIONAL STANDARD ISO 2692:2021(E)
Geometrical product specifications (GPS) — Geometrical
tolerancing — Maximum material requirement (MMR),
least material requirement (LMR) and reciprocity
requirement (RPR)
1 Scope

This document defines the maximum material requirement (MMR), the least material requirement

(LMR) and the reciprocity requirement (RPR). These requirements can only be applied to linear

features of size of cylindrical type or two parallel opposite planes type.

These requirements are often used to control specific functions of workpieces where size and geometry

are interdependent, for example to fulfil the functions “assembly of parts” (for MMR) or “minimum wall

thickness” (for LMR). However, the MMR and LMR can also be used to fulfil other functional design

requirements.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 1101:2017, Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form,

orientation, location and run-out

ISO 5458, Geometrical product specifications (GPS) — Geometrical tolerancing — Pattern and combined

geometrical specification

ISO 5459:2011, Geometrical product specifications (GPS) — Geometrical tolerancing — Datums and datum

systems

ISO 14405-1, Geometrical product specifications (GPS) — Dimensional tolerancing — Part 1: Linear sizes

ISO 17450-1:2011, Geometrical product specifications (GPS) — General concepts — Part 1: Model for

geometrical specification and verification

ISO 17450-3, Geometrical product specifications (GPS) — General concepts — Part 3: Toleranced features

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 5459, ISO 14405-1, ISO 17450-1

and ISO 17450-3 and the following 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
integral feature

geometrical feature belonging to the real surface of the workpiece or to a surface model

Note 1 to entry: An integral feature is intrinsically defined, for example skin of the workpiece.

© ISO 2021 – All rights reserved 1
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SIST EN ISO 2692:2021
ISO 2692:2021(E)
[SOURCE: ISO 17450-1:2011, 3.3.5, modified — Notes 2 and 3 to entry removed.]
3.2
feature of linear size

geometrical feature, having one or more intrinsic characteristics, only one of which may be considered

as variable parameter, that additionally is a member of a “one parameter family”, and obeys the

monotonic containment property for that parameter

EXAMPLE 1 A single cylindrical hole or shaft is a feature of linear size. Its linear size is its diameter.

EXAMPLE 2 Two parallel opposite plane surfaces are a feature of linear size. Their linear size is the distance

between the two parallel opposite planes.

[SOURCE: ISO 17450-1:2011, 3.3.1.5.1, modified — Notes to entry removed; EXAMPLE 2 replaced.]

3.3
derived feature

geometrical feature, which does not exist physically on the real surface of the workpiece and which is

not natively a nominal integral feature (3.1)

Note 1 to entry: A derived feature can be established from a nominal integral surface, an associated integral

surface or an extracted integral surface. It is qualified respectively as a nominal derived feature, an associated

derived feature or an extracted derived feature.

Note 2 to entry: The centre point, the median line and the median surface defined from one or more integral

features (3.1) are types of derived features.

EXAMPLE 1 The median line of a cylinder is a derived feature obtained from the cylindrical surface, which is

an integral feature (3.1). The axis of the nominal cylinder is a nominal derived feature.

EXAMPLE 2 The median surface of two parallel opposite planes is a derived feature obtained from the two

parallel opposite planes, which constitute an integral feature (3.1). The median plane of the nominal two parallel

opposite planes is a nominal derived feature.
[SOURCE: ISO 17450-1:2011, 3.3.6, modified.]
3.4
maximum material size
MMS

value equal to the upper limit of size (ULS) or to the largest ULS in case

of multiple size specifications

Note 1 to entry: An MMS can be defined for any of the size characteristics in ISO 14405-1.

Note 2 to entry: ULS is defined in ISO 14405-1.
3.5
maximum material size
MMS

value equal to the lower limit of size (LLS) or to the smallest LLS in

case of multiple size specifications

Note 1 to entry: An MMS can be defined for any of the size characteristics in ISO 14405-1.

Note 2 to entry: LLS is defined in ISO 14405-1.
3.6
least material size
LMS

value equal to LLS or to the smallest LLS in case of multiple size

specifications

Note 1 to entry: An LMS can be defined for any of the size characteristics in ISO 14405-1.

2 © ISO 2021 – All rights reserved
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SIST EN ISO 2692:2021
ISO 2692:2021(E)
Note 2 to entry: LLS is defined in ISO 14405-1.
3.7
least material size
LMS

value equal to ULS or to the largest ULS in case of multiple size

specifications

Note 1 to entry: An LMS can be defined for any of the size characteristics in ISO 14405-1.

Note 2 to entry: ULS is defined in ISO 14405-1.
3.8
maximum material virtual size
MMVS
value equal to the size of the maximum material virtual condition (3.9)

Note 1 to entry: MMVS can be directly indicated (see 4.1.3) or calculated from the maximum material size (3.4,

3.5) and the geometrical tolerance (see 4.1.2)
3.9
maximum material virtual condition
MMVC

state of associated feature with size equal to maximum material virtual size (3.8)

Note 1 to entry: MMVC is a perfect form condition of the feature of linear size (3.2).

Note 2 to entry: MMVC includes an orientation constraint (in accordance with ISO 1101 and ISO 5459) of the

associated feature when the geometrical specification is an orientation specification (see Figure A.3). MMVC

includes a location constraint (in accordance with ISO 1101 and ISO 5459) of the associated feature when the

geometrical specification is a location specification (see Figure A.4).
Note 3 to entry: See examples in Annex A.
3.10
least material virtual size
LMVS
value equal to the size of the least material virtual condition (3.11)

Note 1 to entry: LMVS can be directly indicated (see 4.1.3) or calculated from the least material size (3.6, 3.7) and

the geometrical tolerance (see 4.1.2)
3.11
least material virtual condition
LMVC
state of associated feature of least material virtual size (3.10)

Note 1 to entry: LMVC is a perfect form condition of the feature of linear size (3.2).

Note 2 to entry: LMVC includes an orientation constraint (in accordance with ISO 1101 and ISO 5459) of the

associated feature when the geometrical specification is an orientation specification. LMVC includes a location

constraint (in accordance with ISO 1101 and ISO 5459) of the associated feature when the geometrical

specification is a location specification (see Figure A.5).
Note 3 to entry: See Figures A.5, A.8, A.9, A.14, A.15.
© ISO 2021 – All rights reserved 3
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SIST EN ISO 2692:2021
ISO 2692:2021(E)
3.12
maximum material requirement
MMR

requirement for a feature of linear size (3.2), defining a geometrical feature of the same type and of

perfect form, with a given value for the intrinsic characteristic (dimension) equal to the maximum

material virtual size (3.8), which limits the non-ideal feature on the outside of the material

Note 1 to entry: MMR is used to control the assemblability of a workpiece.
Note 2 to entry: See also 4.2.
3.13
least material requirement
LMR

requirement for a feature of linear size (3.2), defining a geometrical feature of the same type and of

perfect form, with a given value for the intrinsic characteristic (dimension) equal to the least material

virtual size (3.10), which limits the non-ideal feature on the inside of the material

Note 1 to entry: LMR is used, for example, to control the minimum wall thickness between two symmetrical or

coaxially located similar features of size.
Note 2 to entry: See also 4.3.
3.14
reciprocity requirement
RPR

additional requirement for a feature of linear size (3.2) indicated in addition to the maximum material

requirement (3.12) or the least material requirement (3.13) to indicate that the size tolerance is increased

by the difference between the geometrical tolerance and the actual geometrical deviation

3.15
external feature of linear size

feature of linear size (3.2) where vectors normal to the surface are directed outward from the material

in a direction opposite to the median feature

Note 1 to entry: The cylindrical surface of a shaft is considered to be an external feature of linear size.

Note 2 to entry: See Figure 1.
Key
1 external feature of linear size
2 normal vectors directed outward from the material
3 median feature (cylinder axis)
Figure 1 — Example of external feature of linear size
4 © ISO 2021 – All rights reserved
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SIST EN ISO 2692:2021
ISO 2692:2021(E)
3.16
internal feature of linear size

feature of linear size (3.2) where vectors normal to the surface are directed outward from the material

in a direction toward the median feature

Note 1 to entry: The cylindrical surface of a hole is considered to be an internal feature of linear size.

Note 2 to entry: See Figure 2.
Key
1 interna
...

SLOVENSKI STANDARD
oSIST prEN ISO 2692:2019
01-julij-2019

Specifikacija geometrijskih veličin izdelka (GPS) - Toleriranje geometrijskih veličin

- Zahteva po maksimalnem materialu, zahteva po minimalnem materialu in zahteva
po usklajenosti materialov (ISO/DIS 2692:2019)

Geometrical product specifications (GPS) - Geometrical tolerancing - Maximum material

requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR)

(ISO/DIS 2692:2019)
Geometrische Produktspezifikation (GPS) - Geometrische Tolerierung - Maximum-
Material-Bedingung (MMR), Minimum-Material-Bedingung (LMR) und
Reziprozitätsbedingung (RPR) (ISO/DIS 2692:2019)

Spécification géométrique des produits (GPS) - Tolérancement géométrique - Exigence

du maximum de matière (MMR), exigence du minimum de matière (LMR) et exigence de
réciprocité (RPR) (ISO/DIS 2692:2019)
Ta slovenski standard je istoveten z: prEN ISO 2692
ICS:
01.100.20 Konstrukcijske risbe Mechanical engineering
drawings
17.040.40 Specifikacija geometrijskih Geometrical Product
veličin izdelka (GPS) Specification (GPS)
oSIST prEN ISO 2692:2019 en,fr,de

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 2692:2019
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oSIST prEN ISO 2692:2019
DRAFT INTERNATIONAL STANDARD
ISO/DIS 2692
ISO/TC 213 Secretariat: BSI
Voting begins on: Voting terminates on:
2019-06-03 2019-08-26
Geometrical product specifications (GPS) — Geometrical
tolerancing — Maximum material requirement (MMR),
least material requirement (LMR) and reciprocity
requirement (RPR)

Spécification géométrique des produits (GPS) — Tolérancement géométrique — Exigence du maximum de

matière (MMR), exigence du minimum de matière (LMR) et exigence de réciprocité (RPR)

ICS: 01.100.20
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ISO/DIS 2692:2019(E)
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oSIST prEN ISO 2692:2019
ISO/DIS 2692:2019(E)
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© ISO 2019

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oSIST prEN ISO 2692:2019
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Contents Page

Foreword ........................................................................................................................................................................................................................................iv

Introduction ..................................................................................................................................................................................................................................v

1 Scope ................................................................................................................................................................................................................................. 1

2 Normative references ...................................................................................................................................................................................... 1

3 Terms and definitions ..................................................................................................................................................................................... 1

4 Maximum material requirement, MMR and least material requirement, LMR ..................................6

4.1 General ........................................................................................................................................................................................................... 6

4.1.1 Maximum material virtual size or least material virtual size specification .................. 6

4.1.2 Indirect determination of virtual size ........................................................................................................... 6

4.1.3 Direct indication of maximum material or least material virtual size .............................. 7

4.1.4 Maximum material or least material requirement applied to several

toleranced features ........................................................................................................................................................ 7

4.1.5 Maximum material or least material requirement with same datum

indication containing maximum material or least material requirement ..................... 7

4.2 Maximum material requirement, MMR ............................................................................................................................. 8

4.2.1 Maximum material requirement for toleranced features with indirect

determination of virtual size ................................................................................................................................. 8

4.2.2 Maximum material requirement for related datum features with indirect

determination of virtual size ................................................................................................................................. 9

4.2.3 Maximum material requirement for toleranced features with direct

indication of virtual size .........................................................................................................................................10

4.2.4 Maximum material requirement for related datum features with direct

indication of virtual size .........................................................................................................................................11

4.3 Least material requirement, LMR ........................................................................................................................................11

4.3.1 Least material requirement for toleranced features with indirect

determination of virtual size ..............................................................................................................................11

4.3.2 Least material requirement for related datum features with indirect

determination of virtual size ..............................................................................................................................12

4.3.3 Least material requirement for toleranced features with direct indication

of virtual size ....................................................................................................................................................................13

4.3.4 Least material requirement for related datum features with direct

indication of virtual size .........................................................................................................................................14

5 Reciprocity requirement, RPR ............................................................................................................................................................14

5.1 General ........................................................................................................................................................................................................14

5.2 Reciprocity requirement and maximum material requirement ................................................................15

5.3 Reciprocity requirement and least material requirement .............................................................................15

Annex A (informative) Examples of tolerancing with , and .......................................................................................16

Annex B (informative) Former practice..........................................................................................................................................................56

Annex C (informative) Concept diagram ........................................................................................................................................................57

Annex D (informative) Use of symbols for geometrical characteristics with or ......................................59

Annex E (informative) Relation to the GPS matrix model............................................................................................................61

Bibliography .............................................................................................................................................................................................................................62

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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 on 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 the following

URL: www .iso .org/iso/foreword .html.

This document was prepared by Technical Committee ISO/TC 213, Dimensional and geometrical product

specifications and verification.

This fourth edition cancels and replaces the third edition (ISO 2692:2014), which has been technically

revised.
The main changes compared to the previous edition are as follows:

— direct indication of maximum material or least material virtual size has been added (see 4.1.3);

— the use of SZ or CZ symbols has been added (see 4.1.4);
— the use of SIM symbol has been added (see 4.1.5).
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Introduction
0.1 General

This document is a geometrical product specification (GPS) standard and is to be regarded as a general

GPS standard (see ISO/TR 14638). It influences the chain links 1, 2 and 3 of the chain of standards on

size of linear “features of size” and form of a line (independent/dependent of a datum), form of a surface

(independent/dependent of a datum), orientation and location of derived features based on “features of

size” and datums also based on “features of size”.

The ISO GPS matrix model given in ISO 14638 gives an overview of the ISO GPS system of which this

document is a part. The fundamental rules of ISO GPS given in ISO 8015 apply to this document and

the default decision rules given in ISO 14253-1 apply to specifications made in accordance with this

document, unless otherwise indicated.

For more detailed information on the relation of this document to the GPS matrix model, see Annex E.

This document covers some frequently occurring workpiece functional cases in design and

tolerancing. The “maximum material requirement”, MMR, covers “assembleability” and the “least

material requirement”, LMR, covers, for example, “minimum wall thickness” of a part. MMR and

LMR requirements allow for the combination of two independent requirements into one collective

requirement or to directly define maximum material or least material virtual condition (see Annex C),

which more accurately simulates the intended function of the workpiece. In some cases of both MMR

and LMR, the “reciprocity requirement”, RPR, can be added.

NOTE 1 In ISO GPS standards, threaded features are often considered as a type of cylindrical feature of size.

However, no rules are defined in this document for how to apply MMR, LMR and RPR to threaded features.

Consequently application of the tools defined in this document for threaded features is risky.

NOTE 2 Consideration of assembleability conditions using MMR or consideration of minimum wall thickness

condition using LMR may lead the designer to choose a 0 tolerance value to avoid rejection of parts that can be

assembled or have minimum wall thickness.
0.2 Information about maximum material requirement, MMR
The assembly of parts depends on the combined effect of
a) the size (of one or more features of size), and

b) the geometrical deviation of the features and their derived features, such as the pattern of bolt

holes in two flanges and the bolts securing them.

The minimum assembly clearance occurs when each of the mating features of size is at its maximum

material size (e.g. the largest bolt size and the smallest hole size) and when the geometrical deviations

(e.g. the form, orientation and location deviations) of the features of size and their derived features

(median line or median surface) are also are fully consuming their tolerances. Assembly clearance

increases to a maximum when the sizes of the assembled features of size are furthest from their

maximum material sizes (e.g. the smallest shaft size and the largest hole size) and when the geometrical

deviations (e.g. the form, orientation and location deviations) of the features of size and their derived

features are zero. It therefore follows that if the sizes of one mating part do not reach their maximum

material size, the indicated geometrical tolerance of the features of size and their derived features may

be increased without endangering the assembly to the other part.

This assembly function is controlled by the maximum material requirement. This requirement is

indicated on drawings by the symbol .
0.3 Information about least material requirement, LMR

The least material requirement is designed to control, for example, the minimum wall thickness,

thereby preventing breakout (due to pressure in a tube), the maximum width of a series of slots, etc.

It is indicated on drawings by the symbol . The least material requirement can also be characterized

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by a collective requirement for the size of a feature of size, the geometrical deviation of the feature of

size (form deviations) or by direct definition of a least material virtual condition and the location of its

derived feature.
0.4 Information about reciprocity requirement, RPR

The reciprocity requirement is an additional requirement, which may be used together with the

maximum material requirement and the least material requirement in cases where it is permitted

— taking into account the function of the toleranced feature(s) — to enlarge the size tolerance when

the geometrical deviation on the actual workpiece does not take full advantage of, respectively, the

maximum material virtual condition or the least material virtual condition.
The reciprocity requirement is indicated on the drawing by the symbol .
0.5 General information about terminology and figures

The terminology and tolerancing concepts in this document have been updated to conform to GPS

terminology, notably that in ISO 286-1, ISO 14405-1, ISO 17450-1 and ISO 17450-3.

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DRAFT INTERNATIONAL STANDARD ISO/DIS 2692:2019(E)
Geometrical product specifications (GPS) — Geometrical
tolerancing — Maximum material requirement (MMR),
least material requirement (LMR) and reciprocity
requirement (RPR)
1 Scope

This document defines the maximum material requirement, the least material requirement and the

reciprocity requirement. These requirements can only be applied to linear features of size of cylindrical

type or opposed planar type.

These requirements are often used to control specific functions of workpieces where size and

geometry are interdependent, e.g. to fulfil the functions “assembly of parts” (for maximum material

requirement) or “minimum wall thickness” (for least material requirement). However, the maximum

material requirement and least material requirement can also be used to fulfil other functional design

requirements.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

ISO 1101, Geometrical product specifications (GPS) — Geometrical tolerancing — Tolerances of form,

orientation, location and run-out

ISO 5459:2011, Geometrical product specifications (GPS) — Geometrical tolerancing — Datums and

datum systems

ISO 14405-1, Geometrical product specifications (GPS) — Dimensional tolerancing — Part 1: Linear sizes

3 Terms and definitions

For the purposes of this document, the terms and definitions given in ISO 5459, ISO 14405-1, ISO 17450-1,

ISO 17450-3 and the following 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
integral feature

geometrical feature belonging to the real surface of the workpiece or to a surface model

Note 1 to entry: An integral feature is intrinsically defined, e.g. skin of the workpiece.

Note 2 to entry: Adapted from ISO 17450-1:2011, definition 3.3.5.
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3.2
feature of size
feature of linear size

geometrical feature, having one or more intrinsic characteristics, only one of which may be considered

as variable parameter, that additionally is a member of a “one parameter family”, and obeys the

monotonic containment property for that parameter

Note 1 to entry: Adapted from ISO 17450-1:2011, definition 3.3.1.5.1. See also ISO 22432:2011, definitions

3.2.5.1.1.1 and 3.2.5.1.1.2 for “one parameter family” and “monotonic containment property”.

EXAMPLE 1 A single cylindrical hole or shaft is a feature of linear size. Its linear size is its diameter.

EXAMPLE 2 Two opposite parallel plane surfaces are a feature of linear size. Its linear size is the distance

between the two opposite parallel planes.
3.3
derived feature

geometrical feature, which does not exist physically on the real surface of the workpiece and which is

not natively a nominal integral feature

Note 1 to entry: A derived feature can be established from a nominal integral surface, an associated integral

surface, or an extracted integral surface. It is qualified respectively as a nominal derived feature, an associated

derived feature, or an extracted derived feature.

Note 2 to entry: The centre point, the median line and the median surface defined from one or more integral

features are types of derived features.
Note 3 to entry: Adapted from ISO 17450-1:2011, definition 3.3.6.

EXAMPLE 1 The median line of a cylinder is a derived feature obtained from the cylindrical surface, which is

an integral feature. The axis of the nominal cylinder is a nominal derived feature.

EXAMPLE 2 The median surface of two opposite parallel planes is a derived feature obtained from the two

opposite parallel planes, which constitute an integral feature. The median plane of the nominal two opposite

parallel planes is a nominal derived feature.
3.4
maximum material condition
MMC

state of the considered extracted feature, where the feature of size is at that limit of size where the

material of the feature is at its maximum everywhere, e.g. minimum hole diameter and maximum shaft

diameter

Note 1 to entry: The term maximum material condition, MMC, is used in this document to indicate, at ideal or

nominal feature level (see ISO 17450-1), which limit of the requirement (upper or lower) is concerned.

Note 2 to entry: The size of the extracted feature at maximum material condition, MMC, can be defined using the

default definition of size, or by one of the special definitions of size given in ISO 14405-1.

Note 3 to entry: The maximum material condition, MMC, as defined in this document, can be used unambiguously

with any definition of size of the extracted feature.
3.5
maximum material size
MMS
dimension defining the maximum material condition of a linear feature of size

Note 1 to entry: Maximum material size, MMS, can be defined by default or by one of several special definitions of

the size of the extracted feature (see ISO 14405-1 and ISO 17450-3).

Note 2 to entry: In this document, maximum material size, MMS is used as a numerical value, therefore no specific

definition of the extracted size is needed to permit unambiguous use of maximum material size, MMS.

Note 3 to entry: See Annex A.
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3.6
least material condition
LMC

state of the considered extracted feature, where the feature of size is at that limit of size where the

material of the feature is at its minimum everywhere, e.g. maximum hole diameter and minimum shaft

diameter

Note 1 to entry: The term least material condition, LMC, is used in this document to indicate, at the ideal or

nominal feature level (see ISO 17450-1), which limit of the requirement (upper or lower) is concerned.

Note 2 to entry: The size at least material condition, LMC, can be defined by default or by several special

definitions of the size of extracted feature (see ISO 14405-1 and ISO 17450-3).

Note 3 to entry: The least material condition, LMC, as defined in this document, can be used unambiguously with

any definition of size of the extracted feature.
3.7
least material size
LMS
dimension defining the least material condition of a feature of size

Note 1 to entry: Least material size, LMS, can be defined by default or by one of several special definitions of the

size of the extracted feature (see ISO 14405-1 and ISO 17450-3).

Note 2 to entry: In this document, least material size, LMS, is used as a numerical value, therefore no specific

definition of the extracted size is needed to permit unambiguous use of least material size, LMS.

Note 3 to entry: See Annex A.
3.8
maximum material virtual size
MMVS

directly indicated size (see 4.1.3) or size generated by the collective effect of the maximum material

size, MMS, of a feature of size and the geometrical tolerance (form, orientation or location) given for the

derived feature of the same feature of size

Note 1 to entry: Maximum material virtual size, MMVS, is a parameter for size used as a numerical value

connected to maximum material virtual condition, MMVC.

Note 2 to entry: If it is not directly indicated on the drawing then for external features, MMVS is the sum of

MMS and the geometrical tolerance, whereas for internal features, it is the difference between MMS and the

geometrical tolerance.
3.9
maximum material virtual condition
MMVC
state of associated feature of maximum material virtual size, MMVS

Note 1 to entry: Maximum material virtual condition, MMVC, is a perfect form condition of the feature of size.

Note 2 to entry: Maximum material virtual condition, MMVC, includes an orientation constraint (in accordance

with ISO 1101 and ISO 5459) when the geometrical specification is an orientation specification (see Figure A.3).

Maximum material virtual condition, MMVC, includes a location constraint (in accordance with ISO 1101 and

ISO 5459) of the associated feature when the geometrical specification is a location specification (see Figure A.4).

Note 3 to entry: See Figures A.1 to A.4, A.6, A.7, A.10 to A.19.
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3.10
least material virtual size
LMVS

directly indicated size (see 4.1.3) or size generated by the collective effect of the least material size,

LMS, of a feature of linear size and the geometrical tolerance (form, orientation or location) given for

the derived feature of the same feature of size

Note 1 to entry: Least material virtual size, LMVS, is a parameter for size used as a numerical value connected to

least material virtual condition, LMVC.

Note 2 to entry: If it is not directly indicated then for external features, LMVS is the difference between LMS and

the geometrical tolerance, whereas for internal features, it is the sum of LMS and the geometrical tolerance.

3.11
least material virtual condition
LMVC
state of associated feature of least material virtual size, LMVS

Note 1 to entry: Least material virtual condition, LMVC, is a perfect form condition of the feature of size.

Note 2 to entry: Least material virtual condition, LMVC, includes an orientation constraint (in accordance

with ISO 1101 and ISO 5459) of the associated feature when the geometrical specification is an orientation

specification. Least material virtual condition, LMVC, includes a location constraint (in accordance with ISO 1101

and ISO 5459) of the associated feature when the geometrical specification is a location specification (see

Figure A.5).
Note 3 to entry: See Figures A.5, A.8, A.9, A.14, A.15.
3.12
maximum material requirement
MMR

requirement for a feature of size, defining a geometrical feature of the same type and of perfect form,

with a given value for the intrinsic characteristic (dimension) equal to MMVS, which limits the non-

ideal feature on the outside of the material

Note 1 to entry: Maximum material requirement, MMR, is used to control the assembleability of a workpiece.

Note 2 to entry: See also 4.2.
3.13
least material requirement
LMR

requirement for a feature of size, defining a geometrical feature of the same type and of perfect form,

with a given value for the intrinsic characteristic (dimension) equal to LMVS, which limits the non-ideal

feature on the inside of the material

Note 1 to entry: Least material requirements, LMR, are used in pairs, e.g. to control the minimum wall thickness

between two symmetrical or coaxially located similar features of size.
Note 2 to entry: See also 4.3.
3.14
reciprocity requirement
RPR

additional requirement for a feature of size indicated in addition to the maximum material requirement,

MMR, or the least material requirement, LMR to indicate that the size tolerance is increased by the

difference between the geometrical tolerance and the actual geometrical deviation

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3.15
external feature of size

feature of linear size where vectors normal to the surface are directed outward from the material in a

direction opposite to the median feature

Note 1 to entry: The cylindrical surface of a shaft is considered to be an external cylindrical feature.

Note 2 to entry: See Figure 1.
Key
a external cylindrical feature
b normal vectors directed outward from the material
c median feature (cylinder axis)
Figure 1 — Example of external cylindrical feature
3.16
internal feature of size

feature of linear size where vectors normal to the surface are directed outward from the material in a

direction toward the median feature
Note 1 to entry: The cylindrical surfa
...

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