Hello.
I have a question regarding a blueprint callout on one of our functional gages. May anyone please explain to me what is a proper way of tolerancing and reading 2 basic dimensions with a surface profile tolerance, (see attached sketch). Please provide me with what should be low and max numbers on the basic dimesnions.
Thank You.

Hello.
I have a question regarding a blueprint callout on one of our functional gages. May anyone please explain to me what is a proper way of tolerancing and reading 2 basic dimensions with a surface profile tolerance, (see attached sketch). Please provide me with what should be low and max numbers on the basic dimesnions.
Thank You.



The basic dimensions specify the "True Profile."

The profile of a surface callout (all around) specifies a minus tolerance zone of .0004" from true profile.

Imagine a .0004" zone all around within which the actual profile must be located.

OK.

Maximum dimensions are .3000" x .2750"
Minimum dimensions are .2992 x .2742


Hope this helps.

Stijloor.

Thank you for a quick answer. Now i have sent this gage out for calibration to a certified calibration lab. They have stated that the basic dimension are as foolows:
.3000 to .2996
.2750 to .2741
I did speak with them regarding what they had ceryfied tha gage to and the aswer that i had received was that,In this case surface profile call out (having a little circle on a dimesnion line) states that it is all around surface profile and you can only apply -.0004 not -.0008.
I am realy confused.:nope:

Thank you for a quick answer. Now i have sent this gage out for calibration to a certified calibration lab. They have stated that the basic dimension are as foolows:
.3000 to .2996
.2750 to .2741
I did speak with them regarding what they had ceryfied tha gage to and the aswer that i had received was that,In this case surface profile call out (having a little circle on a dimesnion line) states that it is all around surface profile and you can only apply -.0004 not -.0008.
I am realy confused.:nope:

You should not be.

Basic dimensions specify true profile. Perfect profile. No tolerance. The all-around profile tolerance zone specifies how much deviation is allowed.

The .0004" profile tolerance zone applies all-around.

So if you look at the .2750 dimension, there's a .0004" zone on the "bottom" and a .0004" zone at the "top." .2750 - (2 x .0004") = .2742".

Look at the appropriate Y14.5M standard.

Hope this helps.

Stijloor.