Standard No.:	GB/T 17851-2010
English Name:	Geometrical Product Specifications(GPS)—Geometrical tolerancing—Datums and datum system
Chinese Name:	产品几何技术规范（GPS）　几何公差　基准和基准体系
Chinese Classification:	J04    Basic standards and general methods
Professional Classification:	GB    National Standard
ICS Classification:	01.100.20 01.100.20    Mechanical engineering drawings 01.100.20
Issued by:	AQSIQ; SAC
Issued on:	2011-1-10
Implemented on:	2011-10-1
Status:	superseded
Superseded by:	GB/T 17851-2022 Geometrical product specifications (GPS)—Geometrical tolerancing—Datums and datum systems
Superseded on:	2023-4-1
Superseding:	GB/T 17851-1999 Geometrical tolerancing Datums and datum system
Language:	English
File Format:	PDF
Word Count:	10000 words
Price(USD):	250.0
Delivery:	via email in 1 business day

1 Scope This standard specifies the definition of datums and datum systems for geometrical tolerancing, indications on technical drawings and practical embodiments. This standard is applicable to the basic rules for establishing datums by using simulated datum features and associated features of datum features. 2 Normative references The following documents contain provisions which, through reference in this text, constitute provisions of this standard. For dated references, subsequent amendments (excluding corrections) to, or revisions of, any of these publications do not apply to this standard, however parties to agreements based on this standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition applies. GB/T 1182 Geometrical product specifications (GPS) - Geometrical tolerancing - Tolerances of form, orientation, location and run-out (GB/T 1182-2008, ISO 1101:2004, IDT) GB/T 16671 Geometrical product specifications (GPS) - Geometrical tolerancing - Maximum material requirement (MMR), least material requirement (LMR) and reciprocity requirement (RPR) (GB/T 16671-2009, ISO 2692:2006, MOD) GB/T 18780.1-2002 Geometrical Product Specification (GPS) - Geometrical features - Part 1: General terms and definitions (ISO 14660-1:1999, IDT) GB/Z 20308 Geometrical Product Specifications (GPS) - Masterplan (GB/Z 20308-2006, ISO/TR 14638:1995, MOD) GB/Z 24637.1-2009 Geometrical Product Specifications (GPS) - General concepts - Part 1: Model for geometrical specification and verification (ISO/TS 17450-1:2005, IDT) 3 Terms and definitions For the purposes of this standard, the terms and definitions given in GB/T 1182, GB/T 16671, GB/T 18780.1-2002 and GB/Z 24637.1-2009 and the following apply.

Foreword II 1 Scope 2 Normative references 3 Terms and definitions 4 Establishing of datums 5 Application of datums 6 Indication of datums and datum systems 7 Datum targets 7.1 Symbols for datum targets 7.2 Application of the datum targets 8 Three-plane datum system Annex A (Informative) Position in GPS matrix model