GB/T 6312-2022Micrometer for measuring pipe wall thicknesses (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 of Standardization Documents" drafted.

This document replaces GB/T 6312-2004 "Wall Thickness Micrometer". Compared with GB/T 6312-2004, except for structural adjustment and editorial changes Besides, the main technical changes are as follows.

a) The wall thickness micrometer with the division value of 0.005mm in the applicable scope is deleted (see Chapter 1 of the 2004 edition);

b) Changed the definition of wall thickness micrometer (see 3.1, 3.1 of the 2004 edition);

c) Delete the terms "maximum allowable error" and "micrometer maximum allowable error" and their definitions (see 3.2 and 3.3 of the 2004 edition);

d) Added basic parameters (see 4.2)

e) Added the requirements for Type I wall thickness micrometer measuring anvil (see 5.4.2);

f) Changed the requirements for type II and III wall thickness micrometer measuring anvils (see 5.4.3, 5.4.2 of the 2004 edition)

g) Delete the specified value of locking change (see 5.7 of the 2004 edition);

h) Added type III wall thickness micrometer (see Figures 3 and 4.1.4);

i) Deleted the requirement for the maximum allowable error of the micrometer head (see 5.10 of the 2004 edition);

j) Added the maximum allowable error requirements for type II and III wall thickness micrometers (see 5.10);

k) The test method for the parallelism of type III wall thickness micrometer is added (see 7.3);

l) The test method for the deformation of the wall thickness micrometer frame of type II and III is added (see 7.5.2);

m) The test method for the maximum allowable error has been changed (see 7.6, 6.3 of the 2004 edition).

1 Scope

This document specifies the type and basic parameters, requirements, inspection conditions and inspection of wall thickness micrometers (excluding electronic digital wall thickness micrometers). method, marking and packaging, etc.

This document is applicable to wall thickness micrometers (not Including electronic digital wall thickness micrometer).

2 Normative references

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, dated citations documents, only the version corresponding to that date applies to this document; for undated references, the latest edition (including all amendments) applies to this document.

GB/T 1216 outside micrometer

GB/T 1800.2 Product Geometric Specification (GPS) Linear Dimension Tolerance ISO Code System Part 2: Standard Tolerance Zone Code and limit deviation table of hole and shaft

GB/T 17163 Basic terminology of geometric measuring instruments

GB/T 17164 Terminology of Geometric Measuring Instruments Product Terminology

3 Terms and Definitions

The terms and definitions defined in GB/T 17163, GB/T 17164 and the following apply to this document.

4 Types and basic parameters