R. I. Nelson wrote:

> So if we have the best tools available to measure the part and they 
> measure the part at 1.0000".

Not really the best tools. Good tools, but you can be sure there are better
ones. (I think you yourself came up with a few links to vendors of betters
tools than the ones you were using.) Judging by the use of inches, you seem
to be US American of the old school. Check out the NIST site for some US
gov info about state of the art measurement precision. 

> now you come along and without ever seeing the part or measuring tools, 
> you state the part  cannot be 1.00000"  

I never said that. Please read what I wrote: '... may vary from 0.99995" to
1.00005"'. If my spotty knowledge of English as a second language doesn't
play games with me, that includes the possibility that it is in fact
1.00000" all around.

> You are assuming it to be incorrect, what are you using to base your
> assumption on.  

I take your word for it, nothing less. You said 'you have the tools to read
to 0.00005".' That's what I based my arguments on. Now did your tools have
a tolerance of 0.00005" or not?

> You have to have some means of proving your assumption or theory  or it
> is just an UNPROVED  assumption or theory .

I just assumed you were telling the truth (about the tolerance of your
instruments) and took it from there. So you tell me: did you tell the
truth?

> Until you could come into that work station with a device proven to be
> more accurate by the Bureau of Standards.  How can you, with any
> credibility,  say that our parts were not zero tolerance.

I can say, and I doubt you will find many that challenge that, that there
is no part -- not made by your company, not by others -- that is "zero
tolerance". Letting aside pride in your workmanship, did you read and
understand the arguments offered here? This is not to say you guys did not
a good or even outstanding job. I'm not the one to judge that, and never
did. But the concept of "zero tolerance" is something different, and by
principle impossible. Simply that. 

> The company I had worked for used and told me to use the term "0
> tolerance" when the part measured 1.00000" with the micrometers we had.

Well, I'm sorry to hear that. It happens all the time that the boss is not
right, and to be able to bring food on the table, we all probably are at
times forced to let this go by without complaining too loudly. But that
doesn't make a wrong right. You should read and focus on the arguments
provided plenty here, and try to explain what you mean with "zero
tolerance" and try to find out whether that makes sense -- independently of
what your ex-boss said. 

If you define "the best tools in a shop" define "zero tolerance"; well,
then I have seen some pretty crude "zero tolerance" pieces :)  If you
define "the best tools on the market" define "zero tolerance", then this is
a moving target, and some tools may be better in some respects while others
are better in others, and it's difficult to say which one defines in the
end the "zero tolerance" criterion. If you define "zero tolerance" with
"when the boss says it is", then we're in bad shape, too, as I'm pretty
sure my boss won't agree with yours. None of these definitions of "zero
tolerance" make a lot of sense to me. The only one that does make sense is
that "zero tolerance" means a tolerance of "+0 -0". And this is impossible
to measure. 

So this meaning of "zero tolerance" is not possible, and that's what we
have been trying to explain so far. How do you define "zero tolerance" so
that it in fact /is/ possible? And that it is possible to achieve with
tools that have a tolerance of 0.00005"?

Gerhard

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