B1.13 is the same as ISO 965-1
I emailed the sectary of ISO and asked about this issue and he replied,
In the ISO/CD 965-1:2012 (ISO/TC1 N 621-1) the clause number is 10.4.2. The new one is in this annex.
In the first paragraph of the chapter 1 (Scope), it said that all the tolerances for the series of threads specified by ISO 261 are given.
For some special series of threads their tolerances are not given in the table 5. In these cases the designer shall give the tolerances by his self. Usually he decides the tolerances by the tolerance formulae.
----- Original Message -----
From: Bruce Osborn
To: 'Frank J Cox Sales'
Cc: BOB DODGE ; firstname.lastname@example.org
Sent: Wednesday, May 23, 2012 12:09 PM
Subject: RE: Metric Revision
After conferring with several Industry colleagues it appears section 6.6.2 of the ASME B1.13 standard only applies to the values in table 12 per ISO 965-1. When calculating values not in the table you do not use this calculation.
We made the same assumption when we developed our software. Please let me know if you have further questions.
Osborn Products Inc.
1127 W Melinda Lane
Phoenix, AZ 85027-2812
ISO 9001:2008, AS9100B Certified
Hi Bruce -
You sent a revision to Dominic Scully changing your metric program. Previously your program calculated P.D. Tolerance and if the calculated tolerance was greater than .25p, you used .25p as the P.D. Tolerance. We believe that this is the proper application of the standard but when I applied your new version, you use the calculated P.D. Tolerance. As an example, try M50.0x0.5 6H. The previous version gives NoGo pd as 49.800mm and the revised version gives 49.808mm. Please check your basis for the change and advise.
Many thanks as always,
Frank J. Cox Sales Ltd
40 West Drive