GB/T 3934-2025Specification of gauges for general purpose screw threads (English PDF)

1 Scope

This document specifies the symbols and descriptions, classifications, tolerances, requirements, inspection and acceptance of general thread gauges (hereinafter referred to as "thread gauges").

Logos and packaging.

This document applies to thread gauges with a thread angle of 60°, a nominal diameter of 1mm to 300mm, and a pitch of 0.2mm to 8mm.

Applicable to the inspection of ordinary threads specified in GB/T 192, GB/T 193, GB/T 196 and GB/T 197.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included.

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

This document.

GB/T 197 Tolerances for Standard Threads

GB/T 14791 Thread Terminology

3 Terms and Definitions

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

4 Symbols and Explanations

The symbols and descriptions listed in Table 1 apply to this document.

Table 1 Symbols and Explanations

Symbol Explanation b1 The width of the clearance groove at the major diameter of the complete internal thread profile.

b2 Clearance groove width at the minor diameter of the complete external thread profile b3 The clearance groove width at the major diameter of the truncated internal thread profile and the clearance groove width at the minor diameter of the truncated external thread profile.

D, d. Basic major diameter of internal and external threads on the workpiece

D2 and d2 are the basic pitch diameters of the internal and external threads of the workpiece.

D1 Basic minor diameter of the internal thread of the workpiece es Upper deviation of the pitch diameter of the external thread of the workpiece

EI Lower deviation of the pitch diameter of the internal thread of the workpiece

F1 is the radial distance from the pitch diameter line to the tip of the straight portion of the tooth flank (towards the tooth crest) within the axial section of the truncated thread profile.

F2 is the radial distance from the pitch diameter line to the end of the straight portion of the tooth flank (towards the root) within the axial section of the truncated thread profile.

H represents the original triangle height of the internal and external threads of the workpiece.

GB/T 10932 | GB/T 1216 | GB/T 1218 | GB/T 6315 | GB/T 4755 | […]