Researching ANSI Y14.5 M - 1982 Dimension and Tolerances and could not find an answer to this issue.

There is a ground SS shaft threaded on one end. It has a .373 ground diameter +.000 -.001 with a circular run out of .001 to Datum A and a ground diameter of.4997 +0000 -0002 which is Datum A.

There is a 0.500 Inch of .312-18UNC-2B thread called for one end of the part.

Straightness of shaft is called out diameter .0005 Max Material Condition to Datum A.

Question:

What if any default tolerance should be used for concentricity of the threaded end?

Thanks in advance for your comments

Researching ANSI Y14.5 M - 1982 Dimension and Tolerances and could not find an answer to this issue.

There is a ground SS shaft threaded on one end. It has a .373 ground diameter +.000 -.001 with a circular run out of .001 to Datum A and a ground diameter of.4997 +0000 -0002 which is Datum A.

There is a 0.500 Inch of .312-18UNC-2B thread called for one end of the part.

Straightness of shaft is called out diameter .0005 Max Material Condition to Datum A.

Question:

What if any default tolerance should be used for concentricity of the threaded end?

Thanks in advance for your comments

First of all, straightness of the shaft may be at MMC but never to a datum. It is always to itself so that requirement is wrong.

If the threaded end does not have a Feature Control Frame with concentricity, then there is not a requirement.

The threaded end must meet the size requirement and one other requirement from Rule#1. One should be able to take a straight tube with the ID the same size as the largest allowable size of the thread, and it should move all the way up the threaded portion. This confirms that the feature is not made larger that its MMC size which includes its form (straightness). This requirement is only applicable if the drawing states in note Complies with ASMEY14.5M-82 or 94.

Hope this helps.