GB/T 20328-2023Circular screwing dies of R series for taper pipe threads (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part 1.Structure and Drafting Rules of Standardization Documents"

Drafting.

This document replaces GB/T 20328-2006 "R series tapered pipe thread circular die". Compared with GB/T 20328-2006, except for the structure

In addition to adjustments and editorial changes, the main technical changes are as follows.

---GB/T 7306.1 and GB/T 7306.2 are changed to informative references;

---Added terms and definitions (see Chapter 3).

This document is modified to adopt ISO 4230.2016 "R Series of Conical Pipe Thread Dies for Hand and Machine Use".

Compared with ISO 4230.2016, this document has made the following structural adjustments.

---Added Chapter 3 Terms and Definitions;

---Chapter 4 corresponds to Chapter 3 in ISO 4230.2016;

---Chapter 5 corresponds to Chapter 4 in ISO 4230.2016;

---Added Chapter 6 Technical Requirements.

The technical differences between this document and ISO 4230.2016 and their reasons are as follows.

---Deleted the normative reference document ISO 2568 and added GB/T 970.2 (see Chapter 6);

---The outer diameter and thickness of individual round dies have been adjusted (see Table 1) to facilitate the use of this document;

---The base distance dimension of the thread has been increased (see Table 1) to facilitate the use of this document;

---In Figure 1, the fastening hole angle value is added to facilitate the use of this document;

---Deleted the concave platform in the structure;

---Deleted dimension E1.

---Added the file code in the mark example (see Chapter 5) to facilitate the use of this document;

---Added technical requirements (see Chapter 6) to facilitate the use of this document;

The following editorial changes have been made to this document.

---Deleted footnote a in Table 1 and added footnote a in Table 1;

---Include the limit deviation of Note 3 in Chapter 3 in Table 1;

---Changed Pitch in Table A.1 in Appendix A to P.

Please note that some content in this document may be subject to patents. The publisher of this document assumes no responsibility for identifying patents.

1 Scope

This document specifies the types, dimensions, marking examples and technical requirements for R series tapered pipe thread circular dies.

This document is applicable to R series conical pipe thread circular die for processing 55° sealed pipe threads (see GB/T 7306.1, GB/T 7306.2)

manufacture.

2 Normative reference documents

The contents of the following documents constitute essential provisions of this document through normative references in the text. Among them, the dated quotations

For undated referenced documents, only the version corresponding to that date applies to this document; for undated referenced documents, the latest version (including all amendments) applies to

this document.

GB/T 970.2 Round die Part 2.Technical conditions

3 Terms and definitions

There are no terms or definitions to be defined in this document.

4 Type Dimensions

The type and basic dimensions of R series tapered pipe thread circular die are as specified in Figure 1 and Table 1.

figure 1