GB/T 24632.2-2024Geometrical product specifications (GPS) - Roundness - Part 2: Specification operators (English PDF)

Foreword

This document is in accordance with the provisions of GB/T 1.1-2020 "Guidelines for standardization work Part

1.Structure and drafting rules for standardization documents" Drafting is required. This document is Part 2 of GB/T 24632 "Product Geometric Technical Specification (GPS) Roundness". GB/T 24632 has been published The following parts. Part

1 Scope

GB/T 24632.2-2024 is the second part of the Chinese GPS standard on roundness and it covers the specification operators. Roundness looks like the simplest of the form tolerances and is not: the value obtained for the same component depends on the reference circle fitted, least squares, minimum zone, maximum inscribed or minimum circumscribed, on the filter applied and its cut-off in undulations per revolution, on the number of points and their distribution, and on the stylus tip radius. A drawing that says roundness 2 micrometres without stating those has not specified anything checkable. This part defines the specification operators that make it checkable: the elements of the operator and the order in which they apply, the association methods and their designation, the filtration and the nesting index, the extraction and the sampling, and the way all of it is indicated on the drawing, with worked examples. For a designer, an inspection department or a metrology software vendor in China, this is the text that makes a roundness callout unambiguous.

This document specifies a complete set of specification operations for the roundness of a single component. This document applies only to the complete roundness profile of a single component.

2 Normative references

The contents of the following documents constitute the essential clauses of this document through normative references in this document. For referenced documents without a date, only the version corresponding to that date applies to this document; for referenced documents without a date, the latest version (including all amendments) applies. in this document. ISO 12181

3 Terms and definitions

For the purpose of this document, the terms and definitions defined in ISO 121811 and ISO 174502 apply. 1) ISO 11562.1996 referenced in ISO 121812.2011 has been abolished and replaced by ISO 1661021.2011.