Reporting Profile of a Surface Results on an Internal Cylindrical Feature

[carlsing]

My drawing requires profile of a surface on an internal cylindrical feature with a basic dimension and relative to a plane at the base of the cylinder. A bilateral tolerance zone is implied.

Assuming perfect form and perpendicularity, the diameter measured oversize.

When reporting the results do I report

a) 2x the (actual diameter - basic diameter) (bi-lateral?)

b) Actual diameter - basic diameter

I've looked and found how to verify if feature is "In-Tolerance" but cannot find where it tells how to calculate results.

Thx

 

[Stijloor]

Re: Reporting Profile of a Surface Results

My drawing requires profile of a surface on an internal cylindrical feature with a basic dimension and relative to a plane at the base of the cylinder. A bilateral tolerance zone is implied.

Assuming perfect form and perpendicularity, the diameter measured oversize.

When reporting the results do I report

a) 2x the (actual diameter - basic diameter) (bi-lateral?)

b) Actual diameter - basic diameter

I've looked and found how to verify if feature is "In-Tolerance" but cannot find where it tells how to calculate results.

Thx

Welcome!

Do you clearly understand the interpretation of "Profile of a Surface?"

It is not to be measured and interpreted as the result of a typical 2-point measurement such as measuring a diameter!! :mg:

Your tolerance (boundary) zone (which is bilateral by default) specifies the total amount within which the actual profile must be located. The permissible variations from true profile are half the tolerance up and half the tolerance down.

Look at ASME Y14.5! (Assuming that this is the standard referenced in the title block.)

Stijloor.

 

[Paul F. Jackson]

Re: reporting profile of a surface results

You should report the deviation in the same fashion that the tolerance is given... a zone size centered on the basic.

a) 2x the (actual diameter - basic diameter) (bi-lateral?)

For additional information you can give the Max and Min radial deviation measured and any other info that may be pertainent to those deciding its fate or how to correct it i.e. the diameters center coordinates and aveerage diameter...

But relative to conformance just as you detailed in "a)"

Paul

 

[carlsing]

Re: Reporting Profile of a Surface Results

Thank you for responding.

I believe I understand how to verify that the feature is "In-Tolerance".

What I'm having trouble understanding is how to correctly calculate and report a condition that falls outside of the allowable tolerance zone.

 

[carlsing]

Re: reporting profile of a surface results

Can you tell me where I can find that in ANSI Y14.5?

I've been pulling my hair out looking for it.

Thank You

 

[Paul F. Jackson]

There are no standards as yet codifing how to report deviations in the U.S. but there is a committee authoring one.

If your tolerance is given [Profile|1|A|B|C]

and your surface basic is [5] from [A|B|C]

and your point measurements are:

4.8, 4.3, 5.2, 5.5, 4.9

Your worst deviation from 5 would be 4.3 and you would report it as:

[Profile|1|A|B|C] is 1.4

This means that it takes a zone of 1.4 to contain the deviation (4.3-5) = (-0.7).

Paul