GB/T 20326-2021Long full-diameter shank taps with recess (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"

Drafting.

This document replaces GB/T 20326-2006 "Tap for Thick Long Shank Machines". Compared with GB/T 20326-2006, the main technical changes

as follows.

a) In the normative references, ISO 529.1993 is deleted, GB/T 968 is added, and ISO 8830.1991 is replaced by GB/T 969

Substitute (see Chapter 2, Chapter 2 of the.2006 edition);

b) The relevant dimensional tolerances in Table 1 are included in the technical requirements of Chapter 5 (see Chapter 5, Table 1 of the.2006 edition);

c) The nominal cutting angle of the tap has been added (see 4.2);

d) Added tap mark (see 4.3);

e) Added technical requirements (see Chapter 5);

f) Increased thread tolerance (see Chapter 6);

g) The contents of the logo and packaging have been changed (see Chapter 7, Appendix A of the.2006 edition);

h) The content of Appendix A "Marks" is adjusted to Chapter 7 of the standard text, and Appendix A "The name in this document is in line with ISO 13399

"The relationship between" (see Chapter 7, Appendix A, Appendix A of the.2006 edition).

This document uses the redrafting method to modify the ISO 8051.2016 ``Long shank machine tap with a nominal diameter of M3 to M10, thick shank

Neck taps.

Compared with ISO 8051.2016, this document has made the following structural adjustments.

---4.1 corresponds to Chapter 3 of ISO 8051.2016;

---Chapter 5 technical requirements have been added;

---Added Chapter 6 thread tolerance;

--- Chapter 7 corresponds to Chapter 4 of ISO 8051.2016, and the content has been changed.

The technical differences between this document and ISO 8051.2016 and the reasons are as follows.

---Regarding normative reference documents, this document has made adjustments with technical differences to adapt to my country's technical conditions and adjustments.

The situation is collectively reflected in Chapter 2 "Normative Reference Documents", and the specific adjustments are as follows.

* Deleted ISO 529.1993;

* Added reference to GB/T 968;

* Replace ISO 8830.1991 (see Chapter 5) with GB/T 969, which is modified to adopt international standards.

---The relevant dimensional tolerances in Table 1 are included in the technical requirements of Chapter 5;

---Increase the nominal cutting angle of the tap, and standardize the geometric angle;

---Added the mark, standard mark;

---Added technical requirements and specification requirements;

---Increase the thread tolerance and standardize the thread accuracy;

---Change the content of the logo and packaging, and standardize the logo and packaging.

This document has also made the following editorial changes.

---Change the standard name to "Tap for Thick Long Shank Machine".

1 Scope

This document specifies the basic requirements for the type and size, technical requirements, thread tolerances, markings and packaging of the thick and long shank machine taps.

This document is applicable to thick and long-handled machine taps with a nominal diameter of M3 to M10.

2 Normative references

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

Only the version corresponding to that date is applicable to this document; for undated reference documents, the latest version (including all amendments) is applicable to

This document.

GB/T 968 tap thread tolerance (GB/T 968-2007, ISO 2857.1973, MOD)

GB/T 969 Technical Requirements for Taps (GB/T 969-2007, ISO 8830.1991, MOD)

3 Terms and definitions

There are no terms and definitions that need to be defined in this document.

4 Type and size

4.1 The type and size of the thick long shank machine taps are in accordance with Figure 1 and Table 1.For the correspondence between names and symbols and ISO 13399, see

Appendix A.

Figure 1 Taps for thick and long shank machine