Can Flatness be a refinement of Profile?
Can Flatness be a refinement of Profile?
(OP)
I will attempt to describe my situation in words:
The part is basically a tin can shape (but thicker than tin) with a flange at the top rim. I want to control the flange area with Profile of .01", but engineer wants the bottom of the flange to be held Flat within .002". For the profile, I will call it out between points A and B. Within A to B is the bottom of the flange that needs to be Flat.
Is this a correct thing to do? Can something be called out as Flat within an area that is being Profiled, as long as the Flatness is held tighter?
Thanks
The part is basically a tin can shape (but thicker than tin) with a flange at the top rim. I want to control the flange area with Profile of .01", but engineer wants the bottom of the flange to be held Flat within .002". For the profile, I will call it out between points A and B. Within A to B is the bottom of the flange that needs to be Flat.
Is this a correct thing to do? Can something be called out as Flat within an area that is being Profiled, as long as the Flatness is held tighter?
Thanks





RE: Can Flatness be a refinement of Profile?
John Acosta, GDTP Senior Level
Manufacturing Engineering Tech
SSG, U.S. Army
Taji, Iraq OIF II
RE: Can Flatness be a refinement of Profile?
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Can Flatness be a refinement of Profile?
RE: Can Flatness be a refinement of Profile?
It just was my thought, that if Profile controls just a single nominally flat feature without reference to datums, then profile essentially is no different from flatness.
In this case tighter flatness requirement will simply override it.
Now, if profile is controlling orientation / location, etc., flatness is legitimate refinement and I join powerhound with "yes".
"For every expert there is an equal and opposite expert"
Arthur C. Clarke Profiles of the future
RE: Can Flatness be a refinement of Profile?
Would Perpendicularity meet both of your requirements in a more elegant manner, or would a tolerance zone perpendicular to the relevant datums not be appropriate?
RE: Can Flatness be a refinement of Profile?
RE: Can Flatness be a refinement of Profile?
"Know the rules well, so you can break them effectively."
-Dalai Lama XIV
RE: Can Flatness be a refinement of Profile?
Randy,
Your sketch sure looks like a "tin can" to me
RE: Can Flatness be a refinement of Profile?