Re: Metric/imperial

D Murphy wrote:

Actually no i don't need a history lesson. But I wasn't talking history in
this case. I was merely pointing out that the standard "inch" is in fact
tied to the the standard meter.

Ack. It now is tied to the meter.
Isn't that frightening for you? ;-)

Wrong. The initial meter was the one in Paris. They invested a lot of
time and effort to find a stable alloy. Lots of investigation and the
highest obtainable accuracy at that time.

How do you figure I'm wrong? I was being a little tongue-in-cheek but
trust me I know what a gage block is, I know why they chose platinum
irridium, and I also know why it's a very poor idea to use a mechanical
device as the standard for length for all other mechanical measuring
devices.

What was wrong is that the meter was defined by the block in Paris not by
some -more or less- wrong math.
And what do you suggest they should have used as reference at that time?
Could they come up with something more stable?


Or are you picking nits with the term "later"? The length was defined
first, then the master reference (Platinum Irridium gage block) was
produced after. In English, that would be considered "later".

<G> The master reference *is* the reference. Even if they made something
wrong with calculating the equatorial length.


They knew that, and used the reference as little as possible. They
developed the alloy for that purpose.

Didn't make the problem go away, hence the change coming below...

Now I need a suggestion what they could have made better at that time.


'Tis true. Not nearly enough sizes and pitches for us finicky Yankee
bastards.

What sizes are you missing?

Does it have to be? Do seconds have to be "human"? Like Volts,
Amperes, Pasqual, Liters, Kilograms... ?

It doesn't have to be. I'm just pointing out that it isn't.

So that wasn't an argument? ;-)

Rarely does everything get divided by tens.

You are mixing things. One foot is how many inches? That question
doesn't exist in the metric system.

Sure it does. Hence the prefixes deci, centi, milli, etc...

The prefixes don't make a new unit. They are just handy factors.
Placeholders for zeroes.

In the case of machining parts, neither system is more "accurate"
than the other.

Nobody said that! And if, he must be stupid.

So you haven't met Cliff?

Should I? :-)))

Hmph, the rest of the world seems to have no problem selling us imperial
fasteners.

Would be interesting to see wether more metric than imperial fasteners are
produced worldwide and how that influences their price.


Feel free to support your bias with some actual numbers. Here's a little
help, we exported over $1 trillion dollars worth of goods last year. Let
me know which country exported more than that.

I hope these numbers don't shock you:
<http://en.wikipedia.org/wiki/List_of_countries_by_exports>
They look even worse if you see them relative to the population.

Oh and by the by, the last time I checked the speedometer in a BMW,
Mercedes, or Volkswagon sold here, it was graduated in miles per hour.

And all screws were imperial? :-)

So
while I don't think that Europeans are making goods "just" for the US
market, they do need to adapt them to be able to sell them here.

They do have to follow local laws or facts. Like crash-test, quality of
gas, ... and the unit on the speedometer.

I've also noticed that Sandvik, Kyocera, Mitsubishi, Iscar, etc.. sell
carbide inserts that are in "inch" dimensions, even in their own
countries. The tool shanks sold here. 3/8", 1/2", 5/8", 3/4", 1" are all
available from manufacturers located in "metric" counties.

Did you actually measure them? They sound too much like 10mm, 12mm, 16mm,
20mm and 25mm. Exactly the sizes of my ER25 collets (except the 25mm).

Anyhow, if you wouldn't ask them for these "odd sizes", they wouldn't exist.
It's you who has to pay for special runs. Not that relevant in high-volume
goods.


Nobody is "insisting" on anything. As I pointed out there really isn't a
huge impetus for change here. Foreigners that want access to our market
need to make some adjustments, just as we adjust to theirs when need be.

OK.

Things could be a whole lot worse.


Nick
.

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