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Hello everyone,
I was just looking at some tool catalogs, and it struck me that since
all the calipers are listed as having accuracies of plus or minus .001
in 6 inches, and most of the micrometers are listed as being plus or
minus .0005-.00015 in 1", that the calipers are just as if not a little
more than accurate as the micrometers. And a little more useful since
you get more than one inch out of them.
But, if that is the case, I don't think anyone would be spending
like 700 dollars on a set of 1-4" micrometers. Can someone enlighten me
here? Or possibly point me to some information explaining this, since
this might make for a pretty long post?
I'm also noticing that the digital stuff doesn't list the accuracies
most of the time. But then there is a set of Mitutoyo 0-6" micrometer
with interchangable anvils and the accuracy is listed as plus or
minus .0002 + .00005 x L/3 where L is the max. measuring length. Pretty
concise listing, right? Then even Starret and Brown and Sharpe will
only have the resolution listed. Very confusing. What gives here?

Dave Kirk

Morning Dave

I find that Micrometers are more accurate than the calipers. I use both. When roughing in, I use Digital calipers because the measurements are done very quick. However when getting close to my final diameter, I switch to my Mitutoyo micrometer. This micrometer can be read both digitally and also directly off the barrel. I prefer to read the measurement off the barrel. I like to see the actual measurement and the alignment of the scribed lines. The battery has long since died, and I havent bothered to replace it. If I were to purchase another micrometer, I would forgo the digital option. Also, one thing that we learnt in the Optical company I work for, that if the Optical trainees get use to the digital micrometers, that when they arent available, they are completely lost.


Ron Peeler
B4 owner

----Original Message Follows----
From: "Dave" <dkirk_4@...>
Reply-To: daltonlathes@...
To: daltonlathes@...
Subject: [daltonlathes] calipers vs. micrometers.
Date: Mon, 19 Jun 2006 10:51:32 -0000

Hello everyone,
I was just looking at some tool catalogs, and it struck me that since
all the calipers are listed as having accuracies of plus or minus .001
in 6 inches, and most of the micrometers are listed as being plus or
minus .0005-.00015 in 1", that the calipers are just as if not a little
more than accurate as the micrometers. And a little more useful since
you get more than one inch out of them.
But, if that is the case, I don't think anyone would be spending
like 700 dollars on a set of 1-4" micrometers. Can someone enlighten me
here? Or possibly point me to some information explaining this, since
this might make for a pretty long post?
I'm also noticing that the digital stuff doesn't list the accuracies
most of the time. But then there is a set of Mitutoyo 0-6" micrometer
with interchangable anvils and the accuracy is listed as plus or
minus .0002 + .00005 x L/3 where L is the max. measuring length. Pretty
concise listing, right? Then even Starret and Brown and Sharpe will
only have the resolution listed. Very confusing. What gives here?

Dave Kirk

As to micrometers versus calipers. Well there is no contest here.
A caliper is only accurate to maybe + or - .001 and that is the very
best ones and in like new condition. A micrometer on the other hand
is a precise tool. Your standard micrometer must meet an AGG 1500
government specification to be sold in the US. Now US Japanese as
well as most European micrometers will pass with flying colors. I
still would not trust a Chinese micrometer to better than .0005.
This I say as we have asked employees to remove there Chinky
micrometer from the building as we find they just will not cut the
mustard.

At my business we have our measuring tools checked and calibrated
every six months. Any tool not meeting the grade are removed from
the building. Company tool or personal. Micrometers are tested to
this tolerance. Fist they anvils have to be dead flat and this is
checked with a device that uses wave lengths of light. Forget what
it is called. Next the micrometer is cleaned and the nut adjusted
for feel. Next it is checked every .100 and must be accurate to no
less than .00005. Most all of the micrometers out there today will
meet this requirement when new

So you see a caliper is good for quick roughing measurements but
when push comes to shove you need a micrometer. I use .00005
resolution digital electronic micrometers at work and here at home.
Trust them they work.

Turk
--- In daltonlathes@..., "Dave" <dkirk_4@...> wrote:

Hello everyone,
I was just looking at some tool catalogs, and it struck me that

since

all the calipers are listed as having accuracies of plus or

minus .001

in 6 inches, and most of the micrometers are listed as being plus

or

minus .0005-.00015 in 1", that the calipers are just as if not a

little

more than accurate as the micrometers. And a little more useful

since

you get more than one inch out of them.
But, if that is the case, I don't think anyone would be

spending

like 700 dollars on a set of 1-4" micrometers. Can someone

enlighten me

here? Or possibly point me to some information explaining this,

since

this might make for a pretty long post?
I'm also noticing that the digital stuff doesn't list the

accuracies

most of the time. But then there is a set of Mitutoyo 0-6"

micrometer

with interchangable anvils and the accuracy is listed as plus or
minus .0002 + .00005 x L/3 where L is the max. measuring length.

Pretty

concise listing, right? Then even Starret and Brown and Sharpe

will

only have the resolution listed. Very confusing. What gives here?

Dave Kirk