ISO INTERNATIONAL STANDARD 5459 Second edition 2011-08-15 Geometrical product specifications (GPS) Geometrical tolerancing Datums and datum systems Spécification géometrique des produits (GPs)-Tolérancement géométrique - References spécifiees et systemes de références spécifiées Reference number ISO 5459:2011(E) @ ISO 2011 IHSunder nse from IHS Not for Resale ISO 5459:2011(E) COPYRIGHTPROTECTEDDOCUMENT @ ISO2011 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, 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 [email protected] Web www.iso.org Published in Switzerland @ ISO 2011 - All rights reserved itted without license from IHS Not for Resale ISO 5459:2011(E) Contents Page Foreword .iv Introduction. 1 Scope 2 Normative references. 3 Terms and definitions 4 Symbols. .6 5 Role of datums... 6 General concepts . 6.1 General ... 6.2 Intrinsic characteristics of surfaces associated with datum features. 6.2.1 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 7.2 Indication of datum features 7.2.1 Datum feature indicator... 7.2.2 Datumfeatureidentifier 18 7.2.3 Datum targets .... 18 7.3 Specification of datums and datum systems, 21 7.4 Indication and meaning of rules ... 7.4.1 General ...... 21 7.4.2 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 Copyrght International OrganizaionforStandardizalonghts reserved ii se from IHS Not for Resale