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trailing zeroes and tolerances 3
- Thread starter tk369
- Start date
You're going to have to look at what your local standards say.
Per ASME Y14.5M-1994 section 1.6.1 mm dimensions do not have trailing 0's so you can't simplistically use the type of block tolerance that varies by number of decimals.
What tolerance is required by function? Don't over rely on block tolerances just because they are there.
Mixing mm dimensions with inch tolerances also looks like a recipe for disaster.
Without knowing more information I'd be tempted to directly tolerance your part.
KENAT,
Have you reminded yourself of faq731-376 recently, or taken a look at posting policies: What is Engineering anyway: faq1088-1484
Per ASME Y14.5M-1994 section 1.6.1 mm dimensions do not have trailing 0's so you can't simplistically use the type of block tolerance that varies by number of decimals.
What tolerance is required by function? Don't over rely on block tolerances just because they are there.
Mixing mm dimensions with inch tolerances also looks like a recipe for disaster.
Without knowing more information I'd be tempted to directly tolerance your part.
KENAT,
Have you reminded yourself of faq731-376 recently, or taken a look at posting policies: What is Engineering anyway: faq1088-1484
Many times ISO tolerance blocks are used with metric drawings. These base the tolerance on nominal dimension size so bigger dimensions get bigger tolerances. To me that makes more sense than the number of decimal places but we don't use either. We only have one default linear tolerance for the entire drawing. If you want a different tolerance you have to call it out on each dimension. At least it cuts down on errors.
As Kenat said, over reliance on tolerance block tolerances is a bad thing especially if they impose tight tolerances.
As Kenat said, over reliance on tolerance block tolerances is a bad thing especially if they impose tight tolerances.
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3
- #5
sheevaraam
Mechanical
If you want +/- 1 tolerance as per your drawing standard, then use one place decimal. If you wanted a looser or tighter tolerance then I would explicitly call it out e.g. 1660 +/- 2 or 1660.0+/- 0.5. Depends on how much deviation from the length you can tolerate on the part.
Well, we modified the Unspecified Tolrance block to say that 0/1 place dimensions have +/-.1 tolerance.
Sheevaraam, you cannot use decimal place holders for tolerance on metroc drawings like in your example:
"1660 +/- 2 or 1660.0+/- 0.5".
It would be:
1660 +/- 2 or 1660 +/- 0.5
You may also want to look at ISO standards for the metric classes of tolerance. A dimension of 5 would have a different tolerance than a dimension of 150 or 1660. Yet, they are all 0 decimal places. It does make sense if you think about it.
"Wildfires are dangerous, hard to control, and economically catastrophic."
Ben Loosli
Sheevaraam, you cannot use decimal place holders for tolerance on metroc drawings like in your example:
"1660 +/- 2 or 1660.0+/- 0.5".
It would be:
1660 +/- 2 or 1660 +/- 0.5
You may also want to look at ISO standards for the metric classes of tolerance. A dimension of 5 would have a different tolerance than a dimension of 150 or 1660. Yet, they are all 0 decimal places. It does make sense if you think about it.
"Wildfires are dangerous, hard to control, and economically catastrophic."
Ben Loosli
Don't bring up ISO 2768, I'm not sure I could take it today.
And appologies for my comment about mixing metric & inch, I realize now the " was part of the quotes not indicating inches.
KENAT,
Have you reminded yourself of faq731-376 recently, or taken a look at posting policies: What is Engineering anyway: faq1088-1484
And appologies for my comment about mixing metric & inch, I realize now the " was part of the quotes not indicating inches.
KENAT,
Have you reminded yourself of faq731-376 recently, or taken a look at posting policies: What is Engineering anyway: faq1088-1484
KENATMatt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
CheckerRon
Mechanical
I did a double take on that one too, KENAT, that is why we discourage using inch marks on mechanical (vs civil engineering) drawings.
- Thread starter
- #12
CheckerRon
Mechanical
That's OK, TK. You were gramatically correct. It was our own eyes that deceived us.
Don't think you "are" off "the" hook for the use "of" quote marks, mister"."
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
Matt Lorono
CAD Engineer/ECN Analyst
Silicon Valley, CA
Lorono's SolidWorks Resources
Co-moderator of Solidworks Yahoo! Group
and Mechnical.Engineering Yahoo! Group
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