GB/T 5796.2-2022Trapezoidal screw threads - Part 2: General plan (English PDF)

Foreword

This document is drafted in accordance with the provisions of GB/T 1.1-2020

"Directives for standardization - Part 1: Rules for the structure and drafting of

standardizing documents".

This document is part 2 of GB/T 5796 "Trapezoidal screw threads". The following parts

of GB/T 5796 have been issued:

--- Part 1: Profiles;

--- Part 2: General plan;

--- Part 3: Basic dimensions;

--- Part 4: Tolerances.

This document replaces GB/T 5796.2-2005 "Trapezoidal screw threads -- Part 2:

General plan". Compared with GB/T 5796.2-2005, except for the structural adjustment

and the editorial revisions, the main technical content changes are as follows:

--- The content of marking of the screw thread is deleted (see Chapter 5; see Chapter

5 of the 2005 edition);

--- GB/T 5796.1 is changed from normative reference to informative reference (see

References; see Chapter 2 of the 2005 edition).

This document is modified from ISO 2902:2016 "ISO metric trapezoidal screw threads

-- General plan".

Compared with ISO 2902:2016, the following structural adjustments are made in this

document:

--- Chapter 4 corresponds to Chapter 4 and Chapter 5 in ISO 2902:2016;

--- Chapter 5 corresponds to Chapter 6 in ISO 2902:2016.

The technical differences between this document and ISO 2902:2016 and the reasons

are as follows:

--- ISO 5408 is changed from informative reference to normative reference and

replaced by GB/T 14791 (see Chapter 3) for the sake of complying with the

writing requirements of Chinese standards;

Trapezoidal screw threads -- Part 2: General plan

1 Scope

This document specifies the diameter and pitch combination series of trapezoidal screw

threads, and the profiles conform to the provisions of GB/T 5796.1.

This document applies primarily to mechanical transmission screw threads, and may

also be used for fastening screw threads.

2 Normative references

The following documents contain the provisions which, through normative reference in

this document, constitute the essential provisions of this document. For the dated

referenced documents, only the versions with the indicated dates are applicable to this

document; for the undated referenced documents, only the latest version (including all

the amendments) is applicable to this document.

GB/T 14791 Screw threads - Vocabulary (GB/T 14791-2013, ISO 5408:2009, IDT)

3 Terms and Definitions

The terms and definitions defined in GB/T 14791 apply to this document.

4 Diameter and pitch series and the selection

The combination series of nominal diameter and pitch of trapezoidal screw threads shall

meet the requirements of Table 1.

In Table 1, the 1st series of diameters shall be preferred; the 2nd series of diameters

shall be selected secondly; the 3rd series of diameters shall be selected last.

In new product designs, the 3rd series of diameters shall not be used.

Select the pitch in the same row as the selected diameter, preferably the pitch in the

thick black frame.

If it is necessary to use a special pitch other than that in the same row of the diameter

selected in Table 1, the pitch specified for the adjacent diameter in the table should be

used.

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