This standard specifies the terms and definitions, classification, symbols, tooth profiles, tolerances, requirements, inspection, marking and packaging of trapezoidal thread gauges with a tooth angle of 30°, a nominal diameter of 8mm to 300mm, and a pitch of 1.5mm to 44mm. The trapezoidal thread gauges specified in this standard are suitable for inspecting single-line trapezoidal threads specified in GB/T5796-1986. GB/T 8124-2004 Technical conditions for trapezoidal thread gauges GB/T8124-2004 Standard download decompression password: www.bzxz.net

ICS17.040.30;21.040.10bzxZ.net
National Standard of the People's Republic of China
GB/T 8124—2004
Replaces GB/T8124—1987
Trapezoidal thread gauges
Technical conditions
Tolerances and general features ofgauges for metric trapezoidal screw threadsIssued on 2004-02-10
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of ChinaStandardization Administration of the People's Republic of China
Implementation on 2004-08-01
This standard replaces GB/T8124—1987 "Technical conditions for trapezoidal thread gauges" from the date of its implementation. Compared with GB/T8124-1987, the main changes of this standard are as follows: the dimension of the width of the thread profile gap groove has been modified (3.2.3 of the 1987 edition; 6.2.5 of this edition); the symmetry tolerance of the thread profile gap groove width has been added (6.2.5, 6.2.6, 6.2.7 of this edition); the adjustment plug gauge requirements of the through and stop thread caliper gauges have been deleted (3.1.1, 4.1.3 of the 1987 edition); the inspection requirements have been added (9 of this edition);
GB/T8124-2004
The requirements for smooth limit gauges for inspecting workpiece threads are incorporated into the appendix (4.2, 5.5 of the 1987 edition; Appendix A of this edition); the profile height of the stop thread ring gauge is incorporated into the appendix (Appendix A of the 1987 edition; Appendix B of this edition); the determination of threads is incorporated into the appendix (1.4 of the 1987 edition; Appendix C of this edition). Appendix A and Appendix C of this standard are normative appendices, and Appendix B is an informative appendix. This standard is proposed by the China Machinery Industry Federation. This standard is under the jurisdiction of the National Technical Committee for Standardization of Measuring Tools and Instruments. This standard was drafted by Harbin Measuring Tools and Cutting Tools Factory. The main drafters of this standard are Wu Ying, Gao Shanming, Yao Xuli, Liu Yongfa, and Zhu Hongjie. The previous versions of the standards replaced by this standard are: GB/T 8124--1987.
1 Scope
Trapezoidal thread gauges
Technical conditions
GB/T8124—2004
This standard specifies the terms and definitions, classification, symbols, tooth profiles, tolerances, requirements, inspections, markings and packaging of trapezoidal thread gauges with a tooth angle of 30°, a nominal diameter of 8mm to 300mm, and a pitch of 1.5mm to 44mm. The trapezoidal thread gauge (hereinafter referred to as "thread gauge") specified in this standard is applicable to the inspection of single-line trapezoidal threads specified in GB/T5796-1986.
2 Normative reference documents
The clauses in the following documents become the clauses of this standard through reference in this standard. For all dated referenced documents, all subsequent amendments (excluding errata) or revisions are not applicable to this standard. However, the parties who reach an agreement based on this standard are encouraged to study whether the latest versions of these documents can be used. For all undated referenced documents, the latest versions are applicable to this standard. GB/T5796.1—1986 Trapezoidal thread profile (eqvISO2092:1977) GB/T5796.2—1986 Trapezoidal thread diameter and pitch series (eqvISO2092:1977) GB/T5796.3—1986 Basic dimensions of trapezoidal threads (eqvISO2093:1977) GB/T5796.4—1986 Tolerances of trapezoidal threads (eqvISO2094:1977) 3 Terms and definitions
The terms and definitions established in GB/T·5796.1—1986 to GB/T5796.4—1986 and the following terms and definitions apply to this standard. 3.1
Gauges for metric trapezoidal screw threads Gauges for metric trapezoidal screw threads have standard trapezoidal thread profiles and can reflect the boundary conditions of the internal and external trapezoidal threads being tested. According to the performance, they are divided into: working thread gauges and checking thread gauges.
Work thread gauges for metric trapezoidal screw threads Thread gauges used by operators in the process of manufacturing workpiece threads. 3.3
Check thread gauges for metric trapezoidal screw threads Thread gauges used in manufacturing working thread ring gauges or checking whether the working thread ring gauges in use are worn. 4 Classification
The names, codes and usage rules of thread gauges listed in Table 1 apply to this standard. 4.1
Through end thread plug gauge
Non-end thread plug gauge
Through end thread ring gauge
Should be screwed together with the internal thread of the workpiece
Usage rules
Allowed to be screwed together with the threaded parts at both ends of the internal thread of the workpiece, and the screwing amount should not exceed two pitches (measured when the gauge is withdrawn). If the pitch of the internal thread of the workpiece is less than or equal to three, it should not be fully screwed in and should be screwed in with the external thread of the workpiece.
GB/T 8124—2004
End stop thread ring gauge
“Through-through” thread plug gauge
“Through-stop” thread plug gauge
“Through-loss” thread plug gauge
“Through-stop” thread plug gauge
“Through-stop” thread plug gauge
“Through-stop” thread plug gauge
“Through-stop” thread plug gauge
Table 1 (continued)
It is allowed to partially screw in with the threads at both ends of the external thread of the workpiece, and the amount of screwing should not exceed two pitches (measured when withdrawing the gauge). If the pitch of the internal thread of the workpiece is less than or equal to three, it should not be fully screwed in. It should be screwed in with the through-end thread ring gauge. It is allowed to screw in with the threaded parts at both ends of the through-end thread ring gauge. The screwing amount should not exceed one pitch (measured when the gauge is withdrawn). It should be screwed in with the stop-end thread ring gauge. It is allowed to screw in with the threaded parts at both ends of the stop-end thread ring gauge. The screwing amount should not exceed one pitch (measured when the gauge is withdrawn). The smooth limit gauge used to inspect the workpiece thread is specified in Appendix A. 5 Symbols The symbols and instructions listed in Table 2 apply to this standard. Table 2
Taz /2
Major diameter of workpiece external thread
Middle diameter of workpiece external thread
Minor diameter on the largest solid tooth profile of workpiece external threadMinor diameter of workpiece internal thread
Middle diameter of workpiece internal thread
Major diameter on the largest solid tooth profile of workpiece internal threadUpper deviation of workpiece external thread middle diameter
Pitch of workpiece internal and external threads
Middle diameter tolerance of workpiece external thread
Middle diameter tolerance of workpiece internal thread
Middle diameter tolerance of through thread ring gauge and stop thread ring gaugeMiddle diameter tolerance of through thread plug gauge and stop thread plug gaugeMiddle diameter tolerance of calibrated thread plug gauge
Pitch deviation of thread gauge
Distance from the center line of the middle diameter tolerance zone of the through thread ring gauge to the upper deviation of the middle diameter of the workpiece external threadDistance from the center line of the middle diameter tolerance zone of the through thread plug gauge to the lower deviation of the middle diameter of the workpiece internal thread The distance from the center line of the pitch diameter tolerance zone of the thread plug gauge (or ring gauge) to its wear limit The distance from the center line of the pitch diameter tolerance zone of the stop thread plug gauge (or ring gauge) to its wear limit The distance from the center line of the pitch diameter tolerance zone of the thread ring gauge to the center line of the pitch diameter tolerance zone of the "through-through" (or "stop-through") thread plug gauge
Half-angle deviation of complete thread profile
Half-angle deviation of truncated thread profile
Gap groove width of truncated thread profile
Symmetry tolerance of gap groove of truncated thread profile In the axial section of the truncated thread profile, the radial distance between the pitch diameter line and the top end of the straight part of the tooth side (towards the tooth top side) In the axial section of the truncated thread profile, the radial distance between the pitch diameter line and the end of the straight part of the tooth side (towards the tooth bottom side) 6 Thread profile of thread gauge
6.1 Complete thread profile
GB/T 8124—2004
6.1.1 The thread profile of the through-end thread plug gauge suitable for checking the effective mid-diameter and major diameter of the internal thread of the workpiece is shown in Figure 1. The illustration is for illustration only.
P+ or ~T
15°±
6.1.2 The thread profile of the "check-through" thread plug gauge suitable for checking the effective mid-diameter of the new through-end thread ring gauge is shown in Figure 1. The illustration is for illustration only.
6.1.3 The thread profile of the "check-through" thread plug gauge and the "check-stop" thread plug gauge suitable for checking the single mid-diameter of the new stop-end thread ring gauge is shown in Figure 1. The illustration is for illustration only. 6.1.4 The thread profile of the “stop-loss” thread plug gauge suitable for inspecting the single mid-diameter using the stop-end thread ring gauge is shown in Figure 1. The figure is for illustration only.
6.1.5 The thread profile of the through-end thread ring gauge suitable for inspecting the effective mid-diameter and minor diameter of the external thread of the workpiece is shown in Figure 2. The figure is for illustration only.
15°±Tg
P+or-Tp
6.1.6 The thread profile groove bottom size of the through-end thread plug gauge, “stop-through” thread plug gauge, “stop-through” thread plug gauge, “stop-stop” thread plug gauge, and “stop-loss” thread plug gauge should not be greater than the maximum size of the minor diameter, and the shape of the thread profile groove bottom should be determined by the manufacturer; the thread profile groove bottom size of the through-end thread ring gauge should not be less than the minimum size of the major diameter; the curvature radius R of the thread profile groove bottom should not be greater than the provisions of Table 3.
GB/T 8124—2004
2、3、4、5
6、7、8、9、10、12
14、16、18、20、22、24、28、32、36、40、446.2 Shortened thread profile
Unit: mm
6.2.1 The thread profile of the stop-end thread plug gauge suitable for checking the single middle diameter of the internal thread of the workpiece is shown in Figure 3. The figure is for illustration only. 6.2.2 The thread profile of the "through-stop" thread plug gauge suitable for checking the single middle diameter of the new through-end thread ring gauge is shown in Figure 3. The figure is for illustration only.
P+or～Tp
6.2.3 The thread profile of the “through-loss” thread plug gauge suitable for testing the single mid-diameter of the through-end thread ring gauge in use is shown in Figure 3. The illustration is for illustration only.
6.2.4 The thread profile of the stop-end thread ring gauge suitable for testing the single mid-diameter of the external thread of the workpiece is shown in Figure 4. The illustration is for illustration only. Diameter
15°±
P+or-Tp
6.2.5 The thread profile gap groove width 6 and symmetry tolerance S shall not be greater than those specified in Table 4; the symmetry tolerance S is shown in Figure 5, and the illustration is for illustration only.
GB/T8124—2004
6.2.6 In the axial section of the thread profile, the radial distance F between the median line and the top of the straight part of the tooth side (towards the top of the tooth) shall not be greater than the provisions of Table 4; in the axial section of the thread profile, the radial distance F2 between the median line and the end of the straight part of the tooth side (towards the root of the tooth) shall be as specified in Table 4. For the profile height h3 of the stop thread ring gauge, see Appendix B. 4
Maximum value
Unit: mm
Minimum value
GB/T 8124—2004
6.2.7 If the actual symmetry deviation is less than the symmetry tolerance S and is approximately equal to twice the difference between the symmetry tolerance S and the actual symmetry deviation, the deviation of the clearance groove width 6 is allowed to exceed. The shape of the thread profile clearance groove and groove bottom should be determined by the manufacturer, but should not enter the profile angle within 15°.
7 Tolerances
7.1 Pitch diameter tolerance
The thread pitch diameter tolerance zone of thread ring gauge and proofreading thread plug gauge is shown in Figure 6. The figure is for illustration only. 7.1.1
Through end thread ring gauge
Workpiece external thread
Pitch diameter upper deviation
Workpiece external thread
Pitch diameter lower deviation
Pitch diameter wear limit
Non-end thread ring gauge
Pitch diameter wear limit
The thread pitch diameter tolerance zone of thread plug gauge is shown in Figure 7. 7.1.2
The figure is for illustration only.
The thread pitch diameter tolerance value and related position elements of thread plug gauge, thread ring gauge and proofreading thread plug gauge shall not be greater than those specified in Table 5. 7. 1.3
Ta2、Tp2
80
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