# [mm] TRAILING ZEROS???

• posted
Question: Can anyone tell me what the standard is for showing trailing
zeros when using metric dimensions? I am using inches as primary, and
mm as secondary dual dimensions. With my current settings SWx omits
the trailing zeros for metric dims. For example, the dimension .079
would read ".079 [2]". I was wondering if this is per ASME Y14.5M? Or
would ".079 [2.00]" be preferred??
Thanks in advance for any help with this question.
-JOSH
• posted
Generally, the 3-place imperial dimension would be followed by a 2-place metric dimension. The metric dimension is usually one decimal place shorter (less?) than the equivalent imperial dimension.
for example: .xxxx [.xxx] .xxx [.xx] .xx [.x]
Arlan M.
• posted
I agree with your general statement, however I was wondering about the special case where the metric dimension is a whole number (i.e. 2.00). SWx wants to shorten this to [2] instead of [2.00], omitting the trailing zeros. I was wondering if this was per ASME Y14.5M? This happens also for metric tolerance dimensions. For example, .560 +.000/-.002 would be shown as [14.22 0/-0.05] in mm. What are the specific rules for leading/trailing zeros??
• posted
Standards I know are that if the nominal dim is 4 place, than the tolerances s/b 4 place regardless. eg. .1234 +.0000/-.0005, not .1234 +0/-.0005. At least that's my last 3 companies practice.
You can fix this in SWx. if you want to show it simply by changing the trailing zero's option to "show" instead of "smart" in the Options\document properties\detail tab....
Scott
• posted
From ASME Y14.5M:
"1.6.1 Millimeter Dimensioning... a) Where the dimension is less than one millilmeter, a zero precedes the decimal point... b) Where the dimension is a whole number, neither the decimal point nor a zero is shown. c)...the last digit to the right of the decimal point is not followed by a zero."
• posted
wow- see that? you learn something new every day! 18 years and I guess I've always missed that part! I've always relied on company practice, (which apparently is/was wrong) and never looked it up! Thanks for the info!
Scott
• posted
J Kimmel!
This is what I like - a direct quote from the source (ASME Y14.5M). I suppose eventually I'll break down and buy my own standard, but until then, I appreciate the help. My primary reference book on this subject is good, but doesn't cover everything.
I knew there must be a reason SWx was doing it this way, but wanted to be sure.
IYM,
FYI, I have my SW options set to "Standard" rather than "Smart". Hmm...I wonder what the difference is?
I think your advise is correct when dimensioning in inches, but I recently noticed that metric dimensions seem to have different standards.
Ah, the joys of a dual-dimensioned world!
Thanks again to all.
-JOSH
• posted
I'm not sure so I just looked at the help file.....I wonder if after you changed it to "show" your document properties have to be adjusted as stated below...
BTW, I notice the first sentence in the help file answered your original topic question..... "conforms to ANSI and ISO standards!) ;-)
Trailing zeros. Select one of three settings:
a.. Smart. Trailing zeros are trimmed for whole metric values. (Conforms to ANSI and ISO standards.)
b.. Show. Dimensions have trailing zeros up to the number of decimal places specified in Tools, Options, Document Properties, Units.
c.. Remove. All trailing zeros are removed.
• posted
The use of trailing zeros is eliminated for Metric dims in the standard, but indiividual can still make use of trailing zero to define tolerance if they want. :) I have found that in a company that uses inch, when a metric drawing is made, it's best to just use the familar understanding of decimal places.
Beyond that, it's also ok to depend on the solid model itself and just use the drawing to idenify important critical (or feature control) dimensions. In that case, each dimension should have a specific tol associated with it anyway, while the remaining undimensioned non-critical features are made directly from the model with some overall general tol applied by the vendor in a way that works best for that vendor.

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