[mm] TRAILING ZEROS???

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

 

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.

 

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??

 

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

 

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."


--
J Kimmel

www.metalinnovations.com

"Cuius testiculos habes, habeas cardia et cerebellum." - When you have
their full attention in your grip, their hearts and minds will follow.

 

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

 

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

 

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.

 

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.