Disposition of Allowances, Tolerance and Crest Clearance for Acme Threads
1.Tolerance Zone Definition.
The definition of the Acme thread is dimensionedb y pitch diameter reference locations in perfect 29 deg thread forms with crest and root limited by the correspondingm ajor and minor diameters with comer fillet limitations. This tolerance zone between the maximum and minimum thread profiles defines the thread. There are additional limitations, within the tolerance zone, on the elements flank angle and lead.
2. Tolerance Direction.
The tolerances on diameters of the internal thread are plus, being applied from the minimum sizes to above the minimum sizes.The tolerances on diameters of the external threads are minus, being applied from the maximum sizes to below the maximum sizes.
3. Tolerances on Major and Minor Diameters.
The tolerances on major and minor diameters of external and internal threads are based on the data in Table 3; the values are listed in Table 4.
4. Tolerance on Pitch Diameter
The pitch diameter tolerances for an external and internal thread of a given classa re the same.T hese tolerancesd etermine the tolerance zone included between the maximum and minimum boundary limits. The tolerance Classes 2G,3G,and 4G are given in Tables 5, 6, and 7.
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Disclaimer:
This data is provided for general information only. The intention is to provide accurate information,regardless,errors may exist in the supplied information. If accuracy is critical, base your final decisions on the data provided in the root document: ANSI/ASME B1.5; If you any request or questions please contact ： sales@fyougauges.com
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