Uniform Thickness Comment 3

[eli28]

Hello,

I saw for the first time an engineering department in which the drawings contain a remark "Uniform Thickness XXX".
Here is an example for making it clear:

I never saw a similar comment and I would like to know if it complies with the ISO Standard (or even any other standard).
I thought that maybe an alternative form is using the profile control of both surfaces and the eccentricity of the inner/outer spheric surfaces.
I think that the UNIFORM THICKNESS = Outer_Surface_Profile + Inner_Surface_Profile + Centers eccentricity limitation
Here is an example of an alternative form of writing the same, at least in my opinion:

 

[mfgenggear]

Yeppers

 

[pmarc]

In ISO, if the size of the theoretically exact feature (TEF) is not defined with a theoretically exact dimension (TED), but with a directly toleranced dimension, the associated profile tolerance shall always include OZ (offset zone) modifier.

From ISO 1660:2017:

 

[eli28]

Thanks!

 

[mfgenggear]

the profile of a surface is over used on cylindrical parts, eg shafts for rotational requirements, direct dimensioning of the diameter, and attributes as runout, total runout, perpendicular . straightness at RFS are easier to mfg and inspect. it is very common in my industry for gear shafts.
now for assemblies is round locating pins or shafts like housings, EG gear boxes that's an other issue.

 

[pmarc]

mfgenggear,

Notice that neither OP's picture nor the figure from the ISO standard given by me show a cylindrical part. If this was a cylindrical part, then the cylindricity tolerance would be the logical choice (as a form control). But since there is no dedicated symbol for sphericity in Y14.5 nor in ISO, the profile tolerance with some extra modifiers is the approach to take. In Y14.5-2018 the modifier would be the 'dynamic profile triangle', in ISO it is OZ.

 

[mfgenggear]

I don't have the latest ASME spec, I will take your professional word for it.
sorry I made a blanket statement, to my opinion it is over used, I see a circle it could many type of parts.
UMAE & RMAE I am sure has it's use or it would not be included in the specification.
in my industry with gears its, useless for detail loose gears. may be different for gear boxes.

 

[pmarc]

mfggenggear,
Really no need to apologize. The dimensioning and tolerancing standards are often compared to a toolbox. A tool that is useful for one person does not have to be useful for other people. The trick is to know which tool to take out of the toolbox depending on the application.