Geometrical product specifications (GPS) - Geometrical tolerancing - Datums and datum systems (ISO 5459:2011)

This International Standard specifies terminology, rules and methodology for the indication and understanding of datums and datum systems in technical product documentation. This International Standard also provides explanations to assist the user in understanding the concepts involved. This International Standard defines the specification operator (see ISO 17450-2) used to establish a datum or datum system. The verification operator (see ISO 17450-2) can take different forms (physically or mathematically) and is not the subject of this International Standard.

Geometrische Produktspezifikation (GPS) - Geometrische Tolerierung - Bezüge und Bezugssysteme (ISO 5459:2011)

ISO 5459 beschreibt die Begriffe, die Regeln, Erklärungen und die Art und Weise, in der Bezüge und Bezugssysteme in technische Produktdokumente eingetragen werden.
ANMERKUNG   Detaillierte Regeln zur Maximum- und Minimum-Material-Bedingung sind in ISO 2692 enthalten

Spécification géométrique des produits (GPS) - Tolérancement géométrique - Références spécifiées et systèmes de références spécifiées (ISO 5459:2011)

L'ISO 5459:2011 spécifie la terminologie, les règles et la méthodologie pour indiquer les références spécifiées et les systèmes de références spécifiées dans la documentation technique de produits. Elle fournit également des explications aidant l'utilisateur à la compréhension des concepts considérés.
L'ISO 5459:2011 définit l'opérateur de spécification utilisé pour établir une référence spécifiée ou un système de références spécifiées. L'opérateur de vérification qui peut prendre différentes formes (physique ou mathématique) ne fait pas l'objet de l'ISO 5459:2011.

Specifikacija geometrijskih veličin izdelka - Geometrijsko toleriranje - Reference in sistemi referenc (ISO 5459:2011)

Ta mednarodni standard določa terminologijo, pravila in metodologijo za indikacijo in razumevanje referenc in sistemov referenc v tehnični dokumentaciji proizvoda. Ta mednarodni standard prav tako zagotavlja pojasnila za pomoč uporabniku pri razumevanju vpletenih konceptov. Ta mednarodni standard določa operaterja specifikacij (glej ISO 17450-2), ki se uporablja za vzpostavitev reference ali sistema referenc. Operater specifikacije (glej ISO 17450-2) lahko prevzame različne oblike (fizične ali matematične) in ni predmet tega mednarodnega standarda.

General Information

Status
Published
Publication Date
14-Sep-2011
Technical Committee
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
02-Sep-2011
Due Date
07-Nov-2011
Completion Date
15-Sep-2011

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2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Geometrische Produktspezifikation (GPS) - Geometrische Tolerierung - Bezüge und Bezugssysteme (ISO 5459:2011)Spécification géométrique des produits (GPS) - Tolérancement géométrique - Références spécifiées et systèmes de références spécifiées (ISO 5459:2011)Geometrical product specifications (GPS) - Geometrical tolerancing - Datums and datum systems (ISO 5459:2011)17.040.40Geometrical Product Specification (GPS)17.040.10Tolerance in ujemiLimits and fitsICS:Ta slovenski standard je istoveten z:EN ISO 5459:2011SIST EN ISO 5459:2011en,fr01-oktober-2011SIST EN ISO 5459:2011SLOVENSKI
STANDARDSIST ISO 5459:19951DGRPHãþD



SIST EN ISO 5459:2011



EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN ISO 5459
August 2011 ICS 01.100.20; 17.040.10 English Version
Geometrical product specifications (GPS) - Geometrical tolerancing - Datums and datum systems (ISO 5459:2011)
Spécification géométrique des produits (GPS) - Tolérancement géométrique - Références spécifiées et systèmes de références spécifiées (ISO 5459:2011)
Geometrische Produktspezifikation (GPS) - Geometrische Tolerierung - Bezüge und Bezugssysteme (ISO 5459:2011)This European Standard was approved by CEN on 18 May 2011.
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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre:
Avenue Marnix 17,
B-1000 Brussels © 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 5459:2011: ESIST EN ISO 5459:2011



EN ISO 5459:2011 (E) 2 Contents Page Foreword .3 SIST EN ISO 5459:2011



EN ISO 5459:2011 (E) 3 Foreword This document (EN ISO 5459:2011) 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 February 2012, and conflicting national standards shall be withdrawn at the latest by February 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights. 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, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of ISO 5459:2011 has been approved by CEN as a EN ISO 5459:2011 without any modification.
SIST EN ISO 5459:2011



SIST EN ISO 5459:2011



Reference numberISO 5459:2011(E)© ISO 2011
INTERNATIONAL STANDARD ISO5459Second edition2011-08-15Geometrical product specifications (GPS) — Geometrical tolerancing — Datums and datum systems Spécification géométrique des produits (GPS) — Tolérancement géométrique — Références spécifiées et systèmes de références spécifiées
SIST EN ISO 5459:2011



ISO 5459:2011(E)
COPYRIGHT PROTECTED DOCUMENT
©
ISO 2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56 • CH-1211 Geneva 20 Tel.
+ 41 22 749 01 11 Fax
+ 41 22 749 09 47 E-mail
copyright@iso.org Web
www.iso.org Published in Switzerland
ii © ISO 2011 – All rights reserved
SIST EN ISO 5459:2011



ISO 5459:2011(E) © ISO 2011 – All rights reserved iii Contents Page Foreword.iv Introduction.v 1 Scope.1 2 Normative references.1 3 Terms and definitions.2 4 Symbols.6 5 Role of datums.7 6 General concepts.9 6.1 General.9 6.2 Intrinsic characteristics of surfaces associated with datum features.10 6.2.1 General.10 6.2.2 A single datum established from a single feature.10 6.2.3 Common datum established from two or more single features simultaneously.10 6.2.4 Datum systems established in a defined sequence from two or more single features.12 6.3 Single datums, common datums and datum systems.12 6.3.1 General.12 6.3.2 Single datums.12 6.3.3 Common datums.14 6.3.4 Datum systems.14 7 Graphical language.17 7.1 General.17 7.2 Indication of datum features.17 7.2.1 Datum feature indicator.17 7.2.2 Datum feature identifier.18 7.2.3 Datum targets.18 7.3 Specification of datums and datum systems.21 7.4 Indication and meaning of rules.21 7.4.1 General.21 7.4.2 Rules.22 Annex A (normative)
Association for datums.37 Annex B (informative)
Invariance classes.47 Annex C (informative)
Examples.49 Annex D (informative)
Former practices.71 Annex E (informative)
Examples of a datum system or a common datum established with contacting features.73 Annex F (normative)
Relations and dimensions of graphical symbols.79 Annex G (informative)
Relationship to the GPS matrix model.80 Bibliography.81
SIST EN ISO 5459:2011



ISO 5459:2011(E) iv © ISO 2011 – All rights reserved 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. 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. ISO 5459 was prepared by Technical Committee ISO/TC 213, Dimensional and geometrical product specification and verification. This second edition cancels and replaces the first edition (ISO 5459:1981), which has been technically revised. SIST EN ISO 5459:2011



ISO 5459:2011(E) © ISO 2011 – All rights reserved v Introduction ISO 5459 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 to 3 of the chain of standards on datums. The ISO/GPS Masterplan given in ISO/TR 14638 gives an overview of the ISO/GPS system of which this standard is a part. The fundamental rules of ISO/GPS given in ISO 8015 apply to this standard and the default decision rules given in ISO 14253-1 apply to specifications made in accordance with this standard unless otherwise indicated. For more detailed information of the relation of this International Standard to the GPS matrix model, see Annex G. For the definitive presentation (proportions and dimensions) of symbols for geometrical tolerancing, see ISO 7083. The previous version of ISO 5459 dealt only with planes, cylinders and spheres being used as datums. There is a need to consider all types of surfaces, which are increasingly used in industry. The definitions of classes of surfaces as given in Annex B are exhaustive and unambiguous. This edition of ISO 5459 applies new concepts and terms that have not been used in previous ISO GPS standards. These concepts are described in detail in ISO/TR 14638, ISO 17450-1 and ISO 17450-2; therefore, it is recommended to refer to these standards when using ISO 5459. This International Standard provides tools to express location or orientation constraints, or both, for a tolerance zone. It does not provide information about the relationship between datums or datum systems and functional requirements or applications.
SIST EN ISO 5459:2011



SIST EN ISO 5459:2011



INTERNATIONAL STANDARD ISO 5459:2011(E) © ISO 2011 – All rights reserved 1 Geometrical product specifications (GPS) — Geometrical tolerancing — Datums and datum systems 1 Scope This International Standard specifies terminology, rules and methodology for the indication and understanding of datums and datum systems in technical product documentation. This International Standard also provides explanations to assist the user in understanding the concepts involved. This International Standard defines the specification operator (see ISO 17450-2) used to establish a datum or datum system. The verification operator (see ISO 17450-2) can take different forms (physically or mathematically) and is not the subject of this International Standard. NOTE The detailed rules for maximum and least material requirements for datums are given in ISO 2692. 2 Normative references The following referenced documents are indispensable for the application 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 128-24:1999, Technical drawings — General principles of presentation — Part 24: Lines on mechanical engineering drawings ISO 1101:2004, Geometrical Product Specifications (GPS) — Geometrical tolerancing — Tolerances of form, orientation, location and run-out ISO 1101:2004/Amd 1:—1), Geometrical Product Specifications (GPS) — Geometrical tolerancing — Tolerances of form, orientation, location and run-out — Amendment 1: Representation of specifications in the form of a 3D model ISO 2692:2006, Geometrical product specifications (GPS) — Geometrical tolerancing — Maximum material requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR) ISO 3098-0, Technical product documentation — Lettering — Part 0: General requirements ISO 3098-5, Technical product documentation — Lettering — Part 5: CAD lettering of the Latin alphabet, numerals and marks ISO 14660-1:1999, Geometrical Product Specifications (GPS) — Geometrical features — Part 1: General terms and definitions ISO 17450-1, Geometrical product specifications (GPS) — General concepts — Part 1: Model for geometrical specification and verification ISO 17450-2, Geometrical product specifications (GPS) — General concepts — Part 2: Basic tenets, specifications, operators and uncertainties ISO 81714-1, Design of graphical symbols for use in the technical documentation of products — Part 1: Basic rules
1) To be published. SIST EN ISO 5459:2011



ISO 5459:2011(E) 2 © ISO 2011 – All rights reserved 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 1101, ISO 2692, ISO 14660-1, ISO 17450-1, ISO 17450-2 and the following apply. 3.1 situation feature point, straight line, plane or helix from which the location and orientation of features, or both, can be defined 3.2 datum feature real (non-ideal) integral feature used for establishing a datum NOTE 1 A datum feature can be a complete surface, a portion of a complete surface, or a feature of size. NOTE 2 An illustration showing the relations between datum feature, associated feature and datum is given in Figure 4. 3.3 associated feature associated feature for establishing a datum ideal feature which is fitted to the datum feature with a specific association criterion NOTE 1 The type of the associated feature is by default the same as the type of the nominal integral feature used to establish the datum (for an exception see 7.4.2.5). NOTE 2 The associated feature for establishing a datum simulates the contact between the real surface of the workpiece and other components. NOTE 3 An illustration showing the relations between datum feature, associated feature and datum is given in Figure 4. 3.4 datum one or more situation features of one or more features associated with one or more real integral features selected to define the location or orientation, or both, of a tolerance zone or an ideal feature representing for instance a virtual condition NOTE 1 A datum is a theoretically exact reference; it is defined by a plane, a straight line or a point, or a combination thereof. NOTE 2 The concept of datums is inherently reliant upon the invariance class concept (see Annex A and Annex B). NOTE 3
Datums with maximum material condition (MMC) or least material condition (LMC) are not covered in this International Standard (see ISO 2692). NOTE 4 When a datum is established, for example, on a complex surface, the datum consists of a plane, a straight line or a point, or a combination thereof. The modifier [SL], [PL] or [PT], or a combination thereof, can be attached to the datum letter to limit the situation feature(s) taken into account relative to the surface. NOTE 5 An illustration showing the relation between datum feature, associated feature and datum is given in Figure 4. 3.5 primary datum datum that is not influenced by constraints from other datums 3.6 secondary datum datum, in a datum system, that is influenced by an orientation constraint from the primary datum in the datum system SIST EN ISO 5459:2011



ISO 5459:2011(E) © ISO 2011 – All rights reserved 3 3.7 tertiary datum datum, in a datum system, that is influenced by constraints from the primary datum and the secondary datum in the datum system 3.8 single datum datum established from one datum feature taken from a single surface or from one feature of size NOTE The invariance class of a single surface can be complex, prismatic, helical, cylindrical, revolute, planar or spherical. A set of situation features defining the datum (see Table B.1) corresponds to each type of single surface. 3.9 common datum datum established from two or more datum features considered simultaneously NOTE To define a common datum, it is necessary to consider the collection surface created by the considered datum features. The invariance class of a collection surface can be complex, prismatic, helical, cylindrical, revolute, planar or spherical (see Table B.1). 3.10 datum system set of two or more situation features established in a specific order from two or more datum features NOTE To define a datum system, it is necessary to consider the collection surface created by the considered datum features. The invariance class of a collection surface can be complex, prismatic, helical, cylindrical, revolute, planar or spherical (see Table B.1). 3.11 datum target portion of a datum feature which can nominally be a point, a line segment or an area NOTE Where the datum target is a point, a line or an area, it is indicated as a datum target point, a datum target line or a datum target area, respectively. 3.12 moveable datum target datum target with a controlled motion 3.13 collection surface two or more surfaces considered simultaneously as a single surface NOTE 1 Table B.1 is used to determine the invariance class of a datum or datum systems when using a collection of surfaces. NOTE 2 Two intersecting planes may be considered together or separately. When the two intersecting planes are considered simultaneously as a single surface, that surface is a collection surface. 3.14 feature of size geometrical shape defined by a linear or angular dimension which is a size NOTE The features of size can be a cylinder, a sphere, two parallel opposite surfaces, a cone or a wedge. [ISO 14660-1:1999, 2.2] NOTE In this International Standard, features which are not features of size according to ISO 14660-1 are used to establish a datum as a feature of size, e.g. a truncated sphere (see the example in C.1.4). SIST EN ISO 5459:2011



ISO 5459:2011(E) 4 © ISO 2011 – All rights reserved 3.15 objective function objective function for association formula that describes the quality of association NOTE 1 In this International Standard, the term “objective function” refers to “objective function for association”. NOTE 2 The objective functions are usually named and mathematically described: maximum inscribed, minimum zone, etc. 3.16 association operation used to fit ideal feature(s) to non-ideal feature(s) according to an association criterion [ISO 17450-1:—, 3.2] 3.17 constraint limitation on the associated feature EXAMPLE Orientation constraint, location constraint, material constraint or intrinsic characteristic constraint. 3.17.1 orientation constraint limitation to one or more rotational degrees of freedom 3.17.2 location constraint limitation to one or more translational degrees of freedom 3.17.3 material constraint additional condition to the location of the associated feature, relative to the material of the feature, while optimizing an objective function NOTE For example, an association constraint can be that all distances between the associated feature and the datum feature are positive or equal to zero, i.e. the associated feature is outside the material. 3.17.4 intrinsic characteristic constraint additional requirement applied to the intrinsic characteristic of an associated feature whether it is considered fixed or variable 3.18 association criterion objective function with or without constraints, defined for an association NOTE 1 Several constraints may be defined for an association. NOTE 2 Association results (associated features) may differ, depending upon the choice of association criterion. NOTE 3 Default association criteria are defined in Annex A. 3.19 integral feature surface or line on a surface NOTE An integral feature is intrinsically defined. [ISO 14660-1:1999, 2.1.1] SIST EN ISO 5459:2011



ISO 5459:2011(E) © ISO 2011 – All rights reserved 5 3.20 contacting feature ideal feature of any type which is different from the nominal feature under consideration and is associated with the corresponding datum feature See Figure 1.
a)
Contacting feature on nominal model b)
Contacting feature on real workpiece Key 1 contacting feature: ideal sphere in contact with the datum feature or the feature under consideration 2 features under consideration: nominal trapezoidal slot (collection of two non-parallel surfaces) 3 datum feature: real feature corresponding to the trapezoidal slot (collection of two non-parallel surfaces) Figure 1 — Example of a contacting feature 3.21 invariance class group of ideal features for which the nominal surface is invariant for the same degrees of freedom NOTE There are seven invariance classes (see Annex B). 3.22 theoretically exact dimension TED dimension indicated on technical product documentation, which is not affected by an individual or general tolerance NOTE 1 For the purpose of this International Standard, the term “theoretically exact dimension” has been abbreviated TED. NOTE 2 A theoretically exact dimension is a dimension used in an operation (e.g. association, partition, collection, …). NOTE 3 A theoretically exact dimension can be a linear dimension or an angular dimension.
NOTE 4 A TED can define ⎯ the extension or the relative location of a portion of one feature,
⎯ the length of the projection of a feature, ⎯ the theoretically exact orientation or location of one feature relative to one or more other features, or ⎯ the nominal shape of a feature. NOTE 5 A TED is indicated by a value in a rectangular frame. [ISO 1101:2004/Amd 1:—, 3.7] SIST EN ISO 5459:2011



ISO 5459:2011(E) 6 © ISO 2011 – All rights reserved 4 Symbols Table 1 gives symbols to identify the datum feature or datum target used to establish a datum. Table 2 gives the list of modifier symbols, which can be associated the datum letter. Table 1 — Datum features and datum target symbols Description Symbol Subclause Datum feature indicator
7.2.1 Datum feature identifier Capital letter (A, B, C, AA, etc.) 7.2.2 Single datum target frame
7.2.3.2 Moveable datum target frame
7.2.3.2 Datum target point
7.2.3.3 Closed datum target line
7.2.3.3 Non-closed datum target line
7.2.3.3 Datum target area
7.2.3.3
SIST EN ISO 5459:2011



ISO 5459:2011(E) © ISO 2011 – All rights reserved 7 Table 2 — Modifier symbols Symbol Description Subclause [PD] Pitch diameter 7.4.2.1 [MD] Major diameter 7.4.2.1 [LD] Minor diameter 7.4.2.1 [ACS] Any cross section 7.4.2.4 [ALS] Any longitudinal section 7.4.2.4 [CF] Contacting feature 7.4.2.5 [DV] Variable distance (for common datum) 7.4.2.7 [PT] (situation feature of type) Point 7.4.2.8 [SL] (situation feature of type) Straight line 7.4.2.8 [PL] (situation feature of type) Plane 7.4.2.8
>< For orientation constraint only 7.4.2.8
Projected (for secondary or tertiary datum) 7.4.2.10
Least material requirement See ISO 2692
Maximum material requirement See ISO 2692
5 Role of datums Datums form part of a geometrical specification (see ISO 1101). Datums are established from real surfaces identified on a workpiece. Datums allow tolerance zones to be located or orientated (see Examples 1 and 2) and virtual conditions to be defined (for example maximum material virtual condition # according to ISO OS9O). The datums can be seen as a means to lock degrees of freedom of a tolerance zone. The number of degrees of freedom of the tolerance zone which are locked depends on the nominal shape of the features utilized to establish the datum or datum system; whether the datum is primary, secondary or tertiary; and on the toleranced characteristic indicated in the geometrical tolerance frame. By default, a datum locks all the degrees of freedom of the tolerance zone that it can lock given its shape and which ⎯ are required by the geometrical characteristic indicated in the tolerance frame, and ⎯ have not already been locked by the preceding datum(s) in the datum system. When a datum locks only orientation degrees of freedom, this shall be indicated by the modifier ><. EXAMPLE 1 The tolerance zone, which is the space between two parallel planes 0,1 mm apart, is constrained in orientation by a 75° theoretically exact angle from the datum. Here, the datum is the situation feature of a cylinder (axis of associated cylinder). See Figure 2. SIST EN ISO 5459:2011



ISO 5459:2011(E) 8 © ISO 2011 – All rights reserved Dimensions in millimetres
a)
Indication on the drawing b)
Illustration of tolerance zone Key 1 datum A constituted by the axis of the associated cylinder Figure 2 — Example of tolerance zone constrained in orientation from a datum EXAMPLE 2 The tolerance zone, which is the space between two parallel planes 0,2 mm apart, is constrained in orientation by a 70° angle from a datum, and in location by the distance 20 mm from the gauge plane positioned perpendicular to the axis of 40° cone where its local diameter is 30 mm. Here, the datum consists of the set of situation features of the cone with a fixed angle of 40°, i.e. the cone axis and the point of intersection between the gauge plane and that axis. See Figure 3. Dimensions in millimetres
a)
Indication on the drawing b)
Illustration of tolerance zone Key 1 datum A constituted by the axis of the associated cone, the point of intersection of the gauging plane and this axis Figure 3 — Example of a tolerance zone constrained in location from a datum SIST EN ISO 5459:2011



ISO 5459:2011(E) © ISO 2011 – All rights reserved 9 6 General concepts 6.1 General Datums and datum systems are theoretically exact geometric features used together with implicit or explicit TEDs to locate or orientate a) tolerance zones for toleranced features, or b) virtual conditions, e.g. in the case of maximum material requirement (see ISO 2692). A datum consists of a set of situation features for an ideal feature (feature of perfect form). This ideal feature is an associated feature which is established from the identified datum features of a workpiece. Datum features may be complete features, or identified portions thereof (see Clause 7). A datum system consists of more than one datum. The geometrical type of these associated features belongs to one of t
...

SLOVENSKI STANDARD
oSIST prEN ISO 5459:2008
01-oktober-2008
Geometrijska specifikacija proizvoda - Geometrijsko toleriranje - Reference in
sistemi referenc (ISO/DIS 5459:2008)
Geometrical product specifications (GPS) - Geometrical tolerancing - Datums and datum
-systems (ISO/DIS 5459:2008)
Geometrische Produktspezifikation (GPS) - Geometrische Tolerierung - Bezüge und
Bezugssysteme (ISO/DIS 5459:2008)
Spécification géométrique des produits (GPS) - Tolérancement géométrique -
Références spécifiées et systèmes de références spécifiées (ISO/DIS 5459:2008)
Ta slovenski standard je istoveten z: prEN ISO 5459
ICS:
17.040.30 Merila Measuring instruments
oSIST prEN ISO 5459:2008 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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oSIST prEN ISO 5459:2008

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oSIST prEN ISO 5459:2008
EUROPEAN STANDARD
DRAFT
prEN ISO 5459
NORME EUROPÉENNE
EUROPÄISCHE NORM
June 2008
ICS

English Version
Geometrical product specifications (GPS) - Geometrical
tolerancing - Datums and datum-systems (ISO/DIS 5459:2008)
Spécification géométrique des produits (GPS) - Geometrische Produktspezifikation (GPS) - Geometrische
Tolérancement géométrique - Références spécifiées et Tolerierung - Bezüge und Bezugssysteme (ISO/DIS
systèmes de références spécifiées (ISO/DIS 5459:2008) 5459:2008)
This draft European Standard is submitted to CEN members for third parallel enquiry. It has been drawn up by the Technical Committee
CEN/TC 290.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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 Management Centre has the
same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN ISO 5459:2008: E
worldwide for CEN national Members.

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oSIST prEN ISO 5459:2008
prEN ISO 5459:2008 (E)
Contents Page
Foreword.3

2

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oSIST prEN ISO 5459:2008
prEN ISO 5459:2008 (E)
Foreword
This document (prEN ISO 5459:2008) 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 document is currently submitted to the third parallel Enquiry.
Endorsement notice
The text of ISO/DIS 5459:2008 has been approved by CEN as a prEN ISO 5459:2008 without any
modification.

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oSIST prEN ISO 5459:2008

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oSIST prEN ISO 5459:2008
DRAFT INTERNATIONAL STANDARD ISO/DIS 5459.3
ISO/TC 213 Secretariat: DS
Voting begins on: Voting terminates on:
2008-06-19 2008-08-19
INTERNATIONAL ORGANIZATION FOR STANDARDIZATION • МЕЖДУНАРОДНАЯ ОРГАНИЗАЦИЯ ПО СТАНДАРТИЗАЦИИ • ORGANISATION INTERNATIONALE DE NORMALISATION
Geometrical product specifications (GPS) — Geometrical
tolerancing — Datums and datum-systems
Spécification géométrique des produits (GPS) — Tolérancement géométrique — Références spécifiées et
systèmes de références spécifiées
[Revision of first edition (ISO 5459:1981)]
ICS 01.100.20; 17.040.10

ISO/CEN PARALLEL ENQUIRY
The CEN Secretary-General has advised the ISO Secretary-General that this ISO/DIS covers a subject
of interest to European standardization. In accordance with the ISO-lead mode of collaboration as
defined in the Vienna Agreement, consultation on this ISO/DIS has the same effect for CEN
members as would a CEN enquiry on a draft European Standard. Should this draft be accepted, a
final draft, established on the basis of comments received, will be submitted to a parallel two-month FDIS
vote in ISO and formal vote in CEN.
To expedite distribution, this document is circulated as received from the committee secretariat.
ISO Central Secretariat work of editing and text composition will be undertaken at publication
stage.
Pour accélérer la distribution, le présent document est distribué tel qu'il est parvenu du
secrétariat du comité. Le travail de rédaction et de composition de texte sera effectué au
Secrétariat central de l'ISO au stade de publication.
THIS DOCUMENT IS A DRAFT CIRCULATED FOR COMMENT AND APPROVAL. IT IS THEREFORE SUBJECT TO CHANGE AND MAY NOT BE
REFERRED TO AS AN INTERNATIONAL STANDARD UNTIL PUBLISHED AS SUCH.
IN ADDITION TO THEIR EVALUATION AS BEING ACCEPTABLE FOR INDUSTRIAL, TECHNOLOGICAL, COMMERCIAL AND USER PURPOSES, DRAFT
INTERNATIONAL STANDARDS MAY ON OCCASION HAVE TO BE CONSIDERED IN THE LIGHT OF THEIR POTENTIAL TO BECOME STANDARDS TO
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RECIPIENTS OF THIS DRAFT ARE INVITED TO SUBMIT, WITH THEIR COMMENTS, NOTIFICATION OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPORTING DOCUMENTATION.
©
International Organization for Standardization, 2008

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oSIST prEN ISO 5459:2008
ISO/DIS 5459.3
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oSIST prEN ISO 5459:2008
ISO/DIS 5459:2008(E)
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oSIST prEN ISO 5459:2008
ISO/DIS 5459:2008(E)
Contents Page
Foreword. v
Introduction . vi
1 Scope. 1
2 Normative references . 1
3 Terms and definitions. 1
4 Role of datums . 4
5 Basic concepts. 6
6 Graphical language. 11
Annex A (informative) Invariance classes. 27
Annex B (normative) Association for datums . 28
Annex C (informative) Examples. 34
C.1 Examples of single datums. 34
C.1.1 Plane. 34
C.1.2 Cylinder . 36
C.1.3 Cone . 38
C.1.4 Sphere . 40
C.1.5 Particular situation feature. 42
C.1.6 Obvious situation feature. 44
C.1.7 Only one situation feature needed . 46
C.1.8 Complex surface . 48
C.1.9 Intersecting planes . 50
C.1.10 Two parallel planes . 52
C.1.11 Three datum targets on a plane. 55
C.2 Examples of common datums . 58
C.2.1 Two coplanar planes. 58
C.2.2 Two coaxial cylinders . 59
C.2.3 Perpendicular plane and cylinder . 62
C.2.4 Two parallel cylinders. 64
C.2.5 Pattern of five cylinders . 67
C.2.6 Two parallel planes . 70
C.3 Examples of datum-systems. 73
C.3.1 Three perpendicular planes . 73
C.3.2 Perpendicular plane and cylinder . 76
Annex D (informative) Former practices . 79
Annex E (informative) Examples of datums established from a complete surface and 2 or
3 datum targets . 81
Annex F (informative) Relationship to the GPS matrix model . 87
Bibliography . 88

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oSIST prEN ISO 5459:2008
ISO/DIS 5459:2008(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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
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.
ISO 5459 was prepared by Technical Committee ISO/TC 213, Dimensional and geometrical product
specifications and verification.
This second edition cancels and replaces the first edition (ISO 5459:1981), which has been technically revised.

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oSIST prEN ISO 5459:2008
ISO/DIS 5459:2008(E)
Introduction
ISO 5459 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 to 3 of the chain of standards on datums.
For more detailed information of the relation of this International Standard to the GPS matrix model, see
Annex F.
For the definitive presentation (proportions and dimensions) of symbols for geometrical tolerancing, see
ISO 7083:1983.
The previous version of ISO 5459 dealt only with planes, cylinders and spheres being used as datums. There
is a need to consider all types of surfaces, which are being increasingly used in industry. The definitions of
classes of surfaces as given in Annex A are exhaustive and unambiguous.
This edition of ISO 5459 applies new concepts and terms that have not been used in previous ISO GPS
standards. These concepts are described in detail in ISO/TR 14638, ISO/TS 17450-1 and ISO/TS 17450-2;
therefore, it is recommended to refer to these standards when using ISO 5459.

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oSIST prEN ISO 5459:2008
DRAFT INTERNATIONAL STANDARD ISO/DIS 5459:2008(E)

Geometrical product specifications (GPS) — Geometrical
tolerancing — Datums and datum-systems
IMPORTANT — ISO/TC 213 is aware that the illustrations included in this Draft International Standard
are not of a quality that is required for use in industry (in terms of full conformity with the standards
prepared by ISO/TC 10 and ISO/TC 213). The illustrations will be corrected prior to the Final Draft
International Standard (FDIS) stage.
1 Scope
This International Standard specifies terminology, rules and methodology for the indication and understanding
of datums and datum-systems in technical product documentation. This International Standard also provides
explanations to assist the user in understanding the concepts involved.
This International Standard defines the specification operator (see ISO/TS 17450-2) used to establish a datum
or datum-system. The verification operator (see ISO/TS 17450-2) can take different forms (physically or
mathematically) and is not the subject of this International Standard.
NOTE The detailed rules concerning maximum and/or least material requirements for datums are given in ISO 2692.
2 Normative references
The following referenced documents are indispensable for the application 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 128-24:1999, Technical drawings — General principles of presentation — Part 24: Lines on mechanical
engineering drawings
ISO 1101:2004, Geometrical Product Specifications (GPS) — Geometrical tolerancing — Tolerances of form,
orientation, location and run-out
ISO 2692:2006, Geometrical product specifications (GPS) — Geometrical tolerancing — Maximum material
requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR)
ISO 14660-1:1999, Geometrical Product Specifications (GPS) — Geometrical features — Part 1: General
terms and definitions
ISO/TS 17450 (all parts), Geometrical product specifications (GPS) — General concepts
3 Terms and definitions
For the purpose of this document, the terms and definitions of ISO 1101, ISO 2692, ISO 14660-1,
ISO/TS 17450-1, ISO/TS 17450-2 and the following apply.
3.1
situation feature
point, straight line, plane or helix, from which the location and/or orientation of features can be defined
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3.2
datum feature
non-ideal integral feature used for establishing a datum
NOTE A datum feature can be a complete surface, a portion of a complete surface, or a feature of size.
3.3
associated feature (for establishing a datum)
ideal feature which is fitted to the datum feature with a specific association criterion
NOTE 1 The type of the associated feature is generally the same as the type of the nominal integral feature used to
establish the datum (see rules W5 and R5).
NOTE 2 The associated feature for establishing a datum simulates the contact between the real surface of the
workpiece and other components of an assembly or the fixture used to locate or orientate the workpiece during
manufacture or inspection.
3.4
datum
one or more situation features of one or more features associated to datum features, selected to define the
location and/or orientation of a tolerance zone or to define the location and/or the orientation of an ideal
feature (in the case of complementary requirements, e.g. maximum material requirement)
NOTE 1 A datum is theoretically exact.
NOTE 2 The concept of datums is inherently reliant upon the invariance class concept (see Annex A).
3.5
single datum
datum established from one datum feature taken on a single surface or from one feature of size
NOTE A single surface can be complex, prismatic, helical, cylindrical, revolute, planar or spherical (see Table A.1).
3.6
common datum
datum established from two or more datum features considered simultaneously
NOTE 1 To define a common datum, it is necessary to consider the collection surface created by the considered datum
features.
NOTE 2 The collection surface can be complex, prismatic, helical, cylindrical, revolute, planar or spherical (see
Table A.1).
3.7
datum-system
datum established from two or more datum features considered in a specific order
NOTE 1 To define a datum-system, it is necessary to consider the collection surface created by the considered datum
features.
NOTE 2 The collection surface can be complex, prismatic, helical, cylindrical, revolute, planar or spherical (see
Table A.1).
3.8
datum target
portion of a datum feature which can be a point, a line or an area
3.9
collection surface
two or more surfaces considered simultaneously as a single surface
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NOTE The invariance class of collection surfaces is used to determine the datums or datum-systems (see 5.3.1).
EXAMPLE Two intersecting planes may be considered together or separately. When the two intersecting planes are
considered simultaneously as a single surface, that surface is a collection surface.
3.10
feature of size
geometrical shape defined by a linear or angular dimension which is a size
NOTE The features of size can be a cylinder, a sphere, two parallel opposite surfaces, a cone or a wedge.
[ISO 14660-1:1999, 2.2]
3.11
objective function (for association)
formula that describes the quality of association
NOTE In this International Standard, the term “objective function” refers to “objective function for association”.
3.12
association
operation used to fit ideal feature(s) to non-ideal feature(s) according to a criterion
[ISO/TS 17450-1:2005, 3.2]
3.13
constraint
additional condition to be satisfied while optimizing an objective function
3.14
association criterion
objective function with or without constraints, defined for association
NOTE 1 Several constraints may be defined for an association.
NOTE 2 Association results (associated features) may differ, dependent upon the choice of association criterion.
3.15
integral feature
surface or line on a surface
NOTE An integral feature is intrinsically defined.
[ISO/TS 14660-1:1999, 2.1.1]
3.16
invariance degree (of an ideal feature)
displacement(s) of the ideal feature for which the feature is kept identical in the space
NOTE It corresponds to the degree of freedom used in kinematics.
[ISO/TS 17450-1:2005, 3.16]
3.17
invariance class
a group of ideal features defined by the same invariance degree
[ISO/TS 17450-1:2005, 3.15]
NOTE See Annex A.
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3.18
theoretically exact dimension
dimension indicated on TPD, which is not affected by individual or general tolerance.
Note 1: For the purpose of this standard, the term ‘theoretically exact dimension’ has been abbreviated TED.
Note 2: A theoretically exact dimension is a dimension used in operation (e.g., association, partition, construction…)
Note 3 : a theoretically exact dimension can be a linear dimension or an angular dimension. It is possible for example to
write theoretically exact angle.
[ISO 1101 Amd1, 3.5]
3.18.1
portion theoretically exact dimension
theoretically exact dimension defining a portion of one feature by its enlargement, or its relative location.
Note 1:  For the purpose of this standard, the term ‘portion theoretically exact dimension’ has been abbreviated TED_P.
Note 2:  A portion theoretically exact dimension is a dimension used for partitioning.
[ISO 1101 Amd1, 3.5.1]
3.18.2
relation theoretically exact dimension
theoretically exact dimension used in geometrical specification to define theoretical relationship between two
features, or to define the nominal shape of the feature.
Note 1:  For the purpose of this standard, the term ‘relation theoretically exact dimension’ has been abbreviated TED_G,
or can be abbreviated TED when no confusion is possible.
[ISO 1101 Amd1, 3.5.2]
4 Role of datums
Geometrical specifications define tolerancing of geometrical features. It limits their geometrical deviations in
relation to their theoretically exact form, orientation and/or location. This limitation is achieved by defining
tolerance zones which confine the toleranced features of workpieces which conform to the specification.
Depending on the application of these tolerance zones, three cases can exist:
⎯ a tolerance zone is free to orient and locate itself to best accommodate the feature it confines, i.e. a form
tolerance;
⎯ a set of tolerance zones is oriented and located collectively, i.e. common zone;
⎯ a tolerance zone is oriented and/or located in relation to other features, i.e. a datum or a datum-system
(see Examples 1 and 2).
Datums are established from identified real surfaces of the workpiece.
Datums can lock some degrees of freedom of a tolerance zone. The number of degrees of freedom locked
depends on the nominal shape of the features utilized to establish the datum or datum-system and the
toleranced characteristic indicated in the considered geometrical tolerance frame.
When a datum or datum-system is indicated in a tolerance frame, the number of degrees of freedom of the
tolerance zone that are unlocked is equal to or greater than the invariance degree of that datum or datum-
system.
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The number of degrees of freedom locked is equal to or less than 6 minus the invariance degree (see
Table A.1 in Annex A).
Consider the case where two nominally cylindrical, non-coaxial surfaces with parallel axes, are used to
establish a datum. In this case, the collection surface is invariant only in one direction (1 translation), so it
belongs to the “prismatic” invariance class (see Table A.1). Indicating the corresponding datum alone in a
tolerance frame can lock up to five degrees of freedom of the tolerance zone, but will leave at least one
degree of freedom (a translation) unlocked.
The orientation of a datum within a datum-system can be constrained by other datums within that system (see
5.3.4). A common datum can impose other types of constraint (see 5.3.3).
EXAMPLE 1 The tolerance zone, which is the space between two parallel planes 0,2 mm apart, is constrained in
orientation by a 75° angle from the datum. Here, the datum is the situation feature of a cylinder (the cylinder axis). See
Figure 1.

a
Datum A.
Figure 1 — Tolerance zone constrained in orientation by a 75° angle from the datum
EXAMPLE 2 The tolerance zone, which is the space between two parallel planes 0,2 mm apart, is constrained in
orientation by a 110° angle from a datum, and in location by the distance 20 mm from the gauge plane (the plane where
the local diameter of the cone with a fixed angle of 40°, is 30 mm). Here, the datum is the set of situation features of the
cone with a fixed angle of 40°, i.e. the cone axis and the point of intersection between the gauge plane and that axis. See
Figure 2.

a
Datum A.
Figure 2 — Tolerance zone constrained in orientation by a 110° angle from the datum
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5 Basic concepts
5.1 General
Datums and datum-systems consist of one or more situation features (see Table A.1).
1)
Datums and datum-systems are theoretically exact geometric features used together with TEDs to orientate
and/or locate:
a) tolerance zones for toleranced features ; or
b) virtual conditions, e.g. in the case of maximum material requirement (see ISO 2692), .
Datums and datum-systems are established from the identified datum features of a workpiece. The datum
features can be complete surfaces or features of size, or identified portions thereof.
The geometric type of these surfaces belongs to one of the following invariance classes (see Annex A):
⎯ spherical (i.e. a sphere);
⎯ planar (i.e. a plane);
⎯ cylindrical (i.e. a cylinder);
2)
⎯ helical (e.g. a threaded surface) ;
⎯ revolute (e.g. a cone or a torus);
⎯ prismatic (e.g. a prism);
⎯ complex (e.g. a free form surface).
NOTE 1 In practice, to resolve the association on the re
...

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