flatness symbol on shaft diameter

[duk748]

hello - this is my 2nd post here regarding the use of a flatness symbol on a round shaft - am i going nuts here or maybe someone here can shed some light on this -
the person who created this drawing has had aerospace experience from a highly visable company & i just am not too sure if i should challange him on the use of this
symbol in this regard - i am attaching a pic for reference - i have never seen this before - thank you in advance

 

[DanStro]

Is this an ISO drawing? If it is I don't know if it's an appropriate callout. If it's an ANSI then I think that cylindricity or maybe straightness, depending on the intent, would be the correct callout.

Han primo incensus

 

[MintJulep]

Go ahead and challenge.

 

[fsincox]

I would challenge that one, too!

 

[KENAT]

Challenge

Posting guidelines faq731-376

http://eng-tips.com/market.cfm?

(probably not aimed specifically at you)
What is Engineering anyway: faq1088-1484​

 

[CheckerHater]

Challenge.

But being myself I am also curious, is datum A axis of the shaft or the same flat feature Flatness is applied to?

 

[duk748]

hello again & thank you so much - datum a is the main shaft dia. itself w/ the flatness datum applied to that same diameter - this is not an iso drawing -
most around here would not even know what iso is let alone try & explain it - it really bothers me how this and other drawings made it through our
shop for manufacturing & even so far as inspection (all done accross the pond) - this also was not just a mistake -
i believe that the person who did this really has no "supposed" knowledge of geo tolerance & then this drawing was used to make similar parts in which the same error occurred -
it has become extremely sloppy all around - thank you for the rant forum & as far as a challange i am way too low on the ladder to challenge an m.e. manager on this -
just glad to know i am not totally nuts - (yet)

 

[pmarc]

duk748,
So if it is not ISO, is there any tolerancing standard invoked on the print? Perhaps ASME Y14.5?
There is another thing that looks suspect. If, by any chance, Rule #1 (aka Envelope Principle) is in charge, switching the symbol to straightness or cylindricty will not help - the value of this geometric tolerance shall not be greater than .025, that is total size tolerance of diameter 50.

 

[duk748]

hello again & thank you - yes you are right - there is no real "standard" applied to this drawing - it is a hodge podge of standards since we have no standard - i believe you are right that the tolerance on the shaft is less then the allowable tolerance of the datum symbol - i have already re-drawn the shaft to correct the problem - it would have taken more time for me to explain the right application
then to just fix the drawing & go on - sad state of affairs here - thank you again