GD&T - I'm seeking calculations used to find part charactoristics. 1

[Proofseeker]

The following charactoristics are used to desribe tolerances of parts for machining and manufacturing purposes.

Flatness of a surface
Angularity of a plane
Position or true position of a point
Profile of a surface

There are standard calculations for each of these attributes. Does anyone have a source for these GD&T calculations? Would you please enlighten me as to where I can find this information. Where is the proof I seek?

 

[JLSeagull]

GD&T?
See ASME Y14.5 for dimensional tolerance and B46.1 for surface roughness.

 

[Proofseeker]

JLSeaguli, Anyone,

Thank you for your reply. Unfortunately I do not have a copy of ASME Y14.5. On the ASME website there are two books (Y14.5M Dimensioning and Tolerancing) and (Y14.5.1M Mathematical Definition of Dimensioning and Tolerancing). I assume that Y14.5.1M is what I need. I am tying to verify calculations used in a gage program to find true position of a point (hole), angularity of a surface, profile of a surface, and flatness of a surface. Can you verify for me that this standard actually has example calculations for these attributes before I purchase?
Thanks

 

[JLSeagull]

This is not an area where I have any knowledge. I skimmed both documents. There are many charts, formulas, definitions, etc. I did not see what I would call example calculations in my brief look. Y14.5M is 250 pages. Y14.5.1 is 87 pages. Your terms true position and angularity are used throughout both documents.

I am sure that others could address this better than me. Does the ASME site include a view of the table of contents, etc.?

 

[steelfab01]

The formula's you seek exist only for true position. There are no "formulas" for determining angularity, profile, and flatness. It is what it is. It is simply deviation from required specifications in the feature control frame. It allows a zone from which you may deviate.

True position is determined by taking the square root of x2 + y2. Where, x and y equal the deviation from nominal of your x and y dimensions.

I hope this helps.

 

[namdac]

This post should be on the Drafting Standards, GD&T Page. You will get a larger response.
Regards,
Namdac