Standard No.:	GB/T 16671-2018
Chinese Name:	产品几何技术规范（GPS） 几何公差 最大实体要求（MMR）、最小实体要求（LMR）和可逆要求（RPR）
English Name:	Geometrical product specifications(GPS)—Geometrical tolerancing—Maximum material requirement(MMR),least material requirement(LMR)and reciprocity requirement(RPR)
Professional Classification:	J04 Basic standards and general methods
ICS Classification:	01.100.20 Mechanical engineering drawings
Issued by:
Issued on:	2018-09-17
Implemented on:	2019-04-01
Status:	VALID
Replace:	GB/T16671-2009 Geometrical product specifications(GPS) - Geometrical tolerancing - Maximum material requirement（MMR），least material requirement（LMR） and reciprocity requirement（RPR）
Language:	English
File Format:	PDF
Word Count:	18000 words
Price(USD):	540 (USD)
Delivery:	via email in 1-5 business day

1 Scope

This standard defines the terms and definitions, basic requirements, drawings and application examples of the maximum material requirement, the least material requirement and the reciprocity requirement. These requirements can only be applied to features of size.

This standard is used to control specific functions of workpieces where size and geometry are interdependent, e.g. to fulfill 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 are also used to fulfill other functional requirements.

Considering this interdependence between size and geometry, the principle of independency defined in GB/T 4249 does not apply when the maximum material requirement, least material requirement, or reciprocity requirement, are used.

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.

GB/T 1182-2018 Geometrical product specifications (GPS) - Geometrical tolerances of form orientation location and run-out (ISO 1101: 2017, IDT)
GB/T 18780.2-2003 Geometrical product specifications (GPS) - Geometrical features - Part 2: Extracted median line of a cylinder and a cone, extracted median surface, local size of an extracted feature (ISO 14660-2: 1999, IDT)
ISO 5459: 2011 Geometrical product specifications (GPS) - Geometrical tolerancing - Datums and datum systems
ISO 14405-1: 2010 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

3 Terms and definitions

For the purposes of this document, the terms and definitions in GB/T 18780.2-2003, ISO 5459: 2011, ISO 14405-1: 2010, and ISO 17450-1: 2011 and the following apply.

3.1

integral feature

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

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

Note 2: Adapted from ISO 17450-1: 2011, definition 3.3.5.