One Inch Micrometer

[big_teee]

I am looking for an inexpensive Micrometer that reads down to .0001 inch.
I bought a cheap one at Harbor Freight that said on the box it is accurate to .0001.
When I got it home all I can get it to read is down to .001 inch.
It's a real nice Mike, but doesn't go down far enough.
Not accurate enough for measuring Magnet wire.
Any Ideas and Thoughts!
Terry

[Bruce Johnson]

Is it a vernier micrometer? Are you familiar with vernier micrometers and how you read them? Standard micrometers read to 0.001" using the graduations on the rotating sleeve. Vernier micrometers have the same basic rotating sleeve, but then they have an additional set of vernier lines going across the top of the barrel which allow you to read the extra digit, down to 0.0001". If the micrometer you bought has the vernier scale, then it is capable of reading down to 0.0001". Being from Harbor Freight, the true accuracy over the whole range may be questionable, but as long as it zeros correctly, then it should be fine for measuring magnet wire.

Here's a WikiPedia page on micrometers; partway down the page is an explanation of the Vernier option.
http://en.wikipedia.org/wiki/Micrometer

[big_teee]

Is it a vernier micrometer? Are you familiar with vernier micrometers and how you read them? Standard micrometers read to 0.001" using the graduations on the rotating sleeve. Vernier micrometers have the same basic rotating sleeve, but then they have an additional set of vernier lines going across the top of the barrel which allow you to read the extra digit, down to 0.0001". If the micrometer you bought has the vernier scale, then it is capable of reading down to 0.0001". Being from Harbor Freight, the true accuracy over the whole range may be questionable, but as long as it zeros correctly, then it should be fine for measuring magnet wire.

Here's a WikiPedia page on micrometers; partway down the page is an explanation of the Vernier option.
Micrometer - Wikipedia, the free encyclopedia

Bruce:
Thanks for the reply.
It is this one.
0 to 1" Range Digital Micrometer
It was on sale for $15.
Not a good price if I can't measure wire with it.
T

[defaced]

It looks from that picture that your micrometer has the vernier marking Bruce is talking about that will allow you to measure down to 0.0001". This is how you read them: How to read vernier micrometers

[big_teee]

Thanks, Bruce, Thanks, Mike!
I think I finally understand.
Mine was a little different, but from the How-To, I adapted it to mine.
Still pretty crude way to read it.
I will practice with it.
Thanks again.
Terry

[tedmich]

this will work better
Precision Digital Micrometer (0.001mm Resolution / 0mm~25mm) - Free Shipping - DealExtreme

[big_teee]

this will work better
Precision Digital Micrometer (0.001mm Resolution / 0mm~25mm) - Free Shipping - DealExtreme

That really is nice.
I can read it, and it showed 4 decimal points.
I wish I had inquired before I purchased mine.
Might get another one later.
It also does inch or MM.
Thanks,
Terry

[defaced]

Warning: Ramblings Ahead.

You have to watch on digital meters, often the 0.000X place is only good to 0.0005". The ones I use at work are like that (I live in a +/- 0.005" world, so I don't really care either way), but it looks like the ones Ted linked to are actually good to 0.0001 inches (+/-0.001 mm in theory is +/- 0.00004). As an aside, I was discussing digital calipers with a wire EDM operator about a year ago. He said he had a set of true 0.0001 digital calipers, Mitutoyo brand I think, and said they were very fussy and difficult to get a good measurements from. Maybe a micrometer would give more consistent results because of how the mechanism works. If you decide to go that route, I'd almost suggest seeing if you can find some locally (or a place that has a good return policy) and try them out with your wire. I should really leave the shop now and go drink a beer....

[tedmich]

it is hard to accurately measure things that small, hell if the material is soft like i dunnow, copper wire coated with plastic, the amount of pressure on the anvils can totally flatten what your trying to measure " its 0.0398 inches, no 0.0392, no...etc"
hell the "build coating" can vary waaay more than 0.0001" I imagine wire guys have something much more purpose built for this on soft material

[Jazz P Bass]

Bruce:
Thanks for the reply.
It is this one.
0 to 1" Range Digital Micrometer
It was on sale for $15.
Not a good price if I can't measure wire with it.

I do not quite get "why" you cannot get your tenth's measurement.
The main spindle is graduated in .250 markings.
The secondary spindle will refine this "crude" measurement down to .001 of the main reading.
The tenths are graduated below the anvil.

[big_teee]

I do not quite get "why" you cannot get your tenth's measurement.
The main spindle is graduated in .250 markings.
The secondary spindle will refine this "crude" measurement down to .001 of the main reading.
The tenths are graduated below the anvil.

Did you read all the posts or just the OP?
I've since figured it out, Maybe.
The Device had no instructions, or nuthing.
This one only has 0-5 graduations.
So to read .0018
You would read .001 and a Half, then the 3 would line up and you would add them together.
So .0015 + .0003 = .0018
Not perfectly Ideal, but You get what you pay for.
If I ever buy another one it will be the Digital one, that reads Metric and SAE.
Thanks Everyone.
B_T

[David Schwab]

Did you read all the posts or just the OP?
I've since figured it out, Maybe.
The Device had no instructions, or nuthing.
This one only has 0-5 graduations.
So to read .0018
You would read .001 and a Half, then the 3 would line up and you would add them together.
So .0015 + .0003 = .0018
Not perfectly Ideal, but You get what you pay for.
If I ever buy another one it will be the Digital one, that reads Metric and SAE.
Thanks Everyone.
B_T

At least that one does have a digital reading. I have an old style one that belonged to my dad. I guess they assume if you are buying a mic that you will know how to read it.

I always forget how to use mine.

[Bruce Johnson]

Yep, that's how you read a vernier micrometer. They've been around for about 150 years in that same basic design. Any machinist or shop student had to learn how to read them. The rolling digital number wheels are a new-fangled addition to keep you from making math errors. The newer-fangled digital electronic readout micrometers are the same thing: a traditional vernier micrometer, with an added display to make it easier to read the first three digits. The fourth digit still needs to be read from the vernier. The one real advantage that the electronic ones have is that they can be zeroed at any point, which can be handy.

You have to recognize that a vernier micrometer is the only relatively inexpensive device for measuring to four place (0.0001") resolution. For doing fine comparisons of magnet wire, like you guys want, that's about your only choice. And that resolution is really only enough for determining wire gauge ranges from samples. Four place resolution and higher gets expensive real fast, and the technique gets more fussy. Most digital electronic calipers (in the under $200 range) are only three place resolution (0.001") or three and a half (0.0015"). That's not enough for measuring magnet wire.

I've offered this before, but if any of you need to do some really accurate wire measurements, I can do them for you. I have a Pratt & Whitney Super Micrometer (yep, that's what it's actually called), which measures to five and a half place resolution (0.000005"). It sits on a bench and weighs about 120 lbs. Back in its day, it cost about $5000 new. An old time machine shop next door closed down, and the owner gave it to me. I don't use it much, but it's here. You can mail me samples and I'll measure them for you.

[J M Fahey]

Respectfully, you should have downloaded (and read) the user manual, available in the same page you linked to.
There it states:

This Micrometer measures items in thousandths of an Inch. View the Display underneath the Thimble Lock to see the results.
To calculate ten thousandths of an inch, refer to the number line on the Thimble. Add the number indicated onto the end of the number in the Display.

Good luck.

[Cygnus X1]

Nice one Bruce, I have seen those but never used them.
Been a machinist since my teens and I have an inherent dislike for digital to this day.
Spend the most money you can stand for the 0-1" Mic.
I have two, a Starrett and a Brown & Sharpe, both with adjustable friction on the handle.
Had both of them since 1981 and they are in fine shape.
Carbide face on both.

Taught by old school toolmakers I can still read my steel rule to .0015" inch!
Although I need to use a magnifier to do it.