Title Block Tollerance Vs. Notes
Title Block Tollerance Vs. Notes
(OP)
Hey guys,
I just had a print brought to my attention that has a standard drawing title block tolerance and then a repeat, fine-tune of that tollerance in the notes (see attached file).
We observe ASME Y14.5M.
This approach doesn't sit right, however, I'm wondering if you guys know of some "fine print" that suggests that finer tollerances supersede drawing block tollerances??
Thanks for your input,
Jack
I just had a print brought to my attention that has a standard drawing title block tolerance and then a repeat, fine-tune of that tollerance in the notes (see attached file).
We observe ASME Y14.5M.
This approach doesn't sit right, however, I'm wondering if you guys know of some "fine print" that suggests that finer tollerances supersede drawing block tollerances??
Thanks for your input,
Jack





RE: Title Block Tollerance Vs. Notes
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RE: Title Block Tollerance Vs. Notes
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RE: Title Block Tollerance Vs. Notes
"Unless Otherwise Specified" should be indicated notes that may vary from the rest of the dwg.
Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
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RE: Title Block Tollerance Vs. Notes
So despite what the title block says this drawing doesn't appear to explicitly comply with 14.5. Block tolerances are dealt with in Y14.1 which I don't sadly have a copy of to hand.
There is an argument that the block tolerances should never get changed because people get used to them and switching them causes confusion. In this case it may be appropriate to have a different 'block tolerance' in the notes, however it would have to be made clear in the notes that this 'block tolerance' supplants the tolerance actually in the title block. This is not done on the drawing you posted. As such the drawing you post is, to me, unclear.
In summary, I believe it could be made to work but your sample doesn't explicitly do so.
KENAT,
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RE: Title Block Tollerance Vs. Notes
When the people fear their government, there is tyranny; when the government fears the people, there is liberty. - Thomas Jefferson
RE: Title Block Tollerance Vs. Notes
Further on KENAT's comment about suppressing trailing zero's on metric drawings & default tolerances, we have always only had one default linear tolerance in our title blocks, regardless of decimal places. It seems to be a much more foolproof system, particularly since we have been forced to have some imperial unit drawings in recent years, much to my disgust.
RE: Title Block Tollerance Vs. Notes
Also, when I say the "block tolerances where the tolerance varies with the amount of decimal places doesn't work well with ASME Y14.5M-1994 " I want to make it clear it was for metric, not inch. It can work well for inch if people actually pay attention to what tolerance they are specifying.
KENAT,
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RE: Title Block Tollerance Vs. Notes
-Break sharp edges bigger than the thickness of the material?
-Does this material come in this thickness?
-Possible problems with anodize after bending tab?
-I agree about the trailing zeros. Some of these dimensions are hard to tell if ".3" or "3".
Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
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RE: Title Block Tollerance Vs. Notes
But I agree with evolDiesel that the method on this drawing leaves too much open for interpretation.
RE: Title Block Tollerance Vs. Notes
In the case of your drawing, the vendor could claim the drawing means that the looser tols are specified. Unless you have it defined somewhere, somehow, the court will likely side with the vendor if this went to trial in a lawsuit.
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
RE: Title Block Tollerance Vs. Notes
There are a lot of good replies, but I like the theme the most ("don't do it that way").
DanStro's reply summed up my feelings on the matter.
This is just another case of a drafter trying to get more drawings done. Who can blame them. But in a court of law, I don't see this holding up.
Thanks again.
RE: Title Block Tollerance Vs. Notes
Chris
SolidWorks/PDMWorks 08 3.1
AutoCAD 08
ctopher's home (updated Aug 5, 2008)
ctopher's blog
SolidWorks Legion