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Trying to teach myself to read and calibrate a micrometer. Can anyone tell me this reading?

Looks like 1.045- looking at an angle and all...

Hammermechanicman said:

Is that a metric micrometer?

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Standard-
0 to 1 inch

upupandaway said:

Looks like 1.045- looking at an angle and all...

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Why did I come up with .9996??

Stryped said:

Why did I come up with .9996??

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That is what I got.

How can I insure I am reading it right and it is accurate?

Well usually you have a copy of the owners manual that give you the needed instructions or at mine did before someone stole the tool.

I see the full line plus a hair of the shadow for 1.0 on the scale. If it less then you wouldn't see the 1.0 line or barely see it. Anyway, that's what I see.

Looking at a video, it appears it has been too long since i used one as I am reading on the wrong side of the line and reading up instead of down.....

the photos show two different readings. Guessing that is a 0 - 1" mic since you did not show that marking, one reading looks to be about .9994" and the other .9996".
Using a mic is more than reading it. It is knowing when to read it, and how to hold it without the heat from your hand changing it. If you lay it in the sun or under a bright lamp that warms it, the reading will change. You also need a standard or gauge block to check it once in awhile, most kits have one in it.

StarTech said:

Well usually you have a copy of the owners manual that give you the needed instructions or at mine did before someone stole the tool.

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Mine did not have instructions. It’s from harbor freight but don’t yell at me……

Well that stinks. I couldn't even find a manual for it online either.

I taught my students to read a mic this way.
1. Numbers running left to right are dollars.
2. Lines between the numbers are quarters.
3. Lines going around the thimble are pennies.
4. Lines on the barrel (1-10) are tenths of a penny.

The reading in you original post is this.
9 dollars. $9.00
3 quarters. .75
5 pennies. .05
6 tenths. .006

Add it up. $9.806
Move decimal point one step left for final measurement. .9806”
Sixth grade students caught on to this method in one class period.

I see $9.0 + .75 + .24 + .004 or .006 ($9.994 or $9.996) depending on the photo. A full revolution is .025" and it is almost that. 4 turns on that one is .1" If one wants to work it backwards, unscrewing it .0004 would make it 1.000" which is barely showing as the 4th hack mark. 1.000" minus .0004 would be .9996". Another way is that is about 1/2 a hatch mark on the barrel from a full1.000" inch. If it was screwed in to the first hatch mark it would be .001" less than 1.000" or .999". Since it is about 1/2 a hatch mark it is about .9995". The fine division is a 4 or a 6 depending on the actual angle the viewer looks at. The photos are not all that good which does not help.

sgkent, you may be correct, but as you said the picture is not very good. If it were as you said we should be able to see a line between 20-0, which would indicate 20-25. I don’t see that, which is why I taught my students read what you see, not what you think it should be. More than likely this is a cheap mic, out of calibration, which is why we disagree.

if my memory serves me, and it may not because I don't use one but a couple times a year these days, 25 and 0 are the same hash. one turn would be 0 to 5, 5+ to 10, 10+ to15, 15+ to 20, and 20+ back to 0 which serves as 25 because the hash marks on the stem reveal every 25. It is really irrelevant. The OP should be not asking someone on the Internet to read his mic. When a master machinist taught me the first thing he did was scold me politely for not putting the mic back in the box when not in use, and leaving it in the sun, and the next thing he did was show me how to hold it so the heat of my hand would not alter the readings. He build Formula One engines, Indy engines and Al Unser Jr was one of his clients - so I tend to trust what Bill taught me when he said, don't lay it in the sun or it will warm up. Whatever you do don't drop it.

Fancy C clamp

Old school Lufkin. Was my father's and i think he got when he worked for the CCC during the depression. Still accurate.

Believe it or not I laid In bed last night and this thread kept running through my mind. Am I making a mistake? YES. Being that this is a vernier micrometer made me not believe my own eyes. Sgkent is correct, I am wrong, another learning experience, not a mistake. Sorry to the OP for leading you in the wrong direction.

1.05"

good example

Stryped said:

How can I insure I am reading it right and it is accurate?

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You can look for a manual online. You'll need to check that your mic is calibrated correctly.
And YouTube usually comes to the rescue to teach us stuff.

I agree the pictures are not great, I read it as .9996. If the Zero on the thimble was on the zero line on the barrell it would be 1.0000"

sgkent said:

I see $9.0 + .75 + .24 + .004 or .006 ($9.994 or $9.996) depending on the photo. A full revolution is .025" and it is almost that. 4 turns on that one is .1" If one wants to work it backwards, unscrewing it .0004 would make it 1.000" which is barely showing as the 4th hack mark. 1.000" minus .0004 would be .9996". Another way is that is about 1/2 a hatch mark on the barrel from a full1.000" inch. If it was screwed in to the first hatch mark it would be .001" less than 1.000" or .999". Since it is about 1/2 a hatch mark it is about .9995". The fine division is a 4 or a 6 depending on the actual angle the viewer looks at. The photos are not all that good which does not help.

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This appears to be correct. That's a good tip to unscrew it to the 1.000 mark, which is easy to identify. Then when you seat it again on the object you're measuring if it moves about half a thousandth, it is about 0.9995. Since I got spoiled by digital micrometers a long time ago, I use this crutch a lot to make sure I don't misread an analog mic (or a digital one with a dead battery). Back it off to the next full .025" mark and then count the thousandths that go by when you close it again.
You can use the vernier scale to read the "tenths" (shorthand that machinists use for ten-thousandths) if you want to go that far. But if you're doing work where tenths are important, then you probably won't be using instruments from Harbor Freight.
A 0-1" mic won't come with a setting standard as you can simply close it all the way and it should read 0.0000. A 1-2" would come with a 1" standard, a 2-3" with a 2" standard, and so on.
New mics come with a spanner that you can use to twist the barrel during calibration so it reads correctly.
If you want to check your 0-1" mic at any measurement other than 0 you'll need gage blocks, or you can measure an object with it and then compare that to what you get with another instrument that you trust.

I have not used this type of micrometer, but I have used (and taught the use of) others.
They can be tricky.
From your first picture here is what I see and what I'm guessing.
You have a fixed scale near the bottom with numbers 0,1,2,...9,0
These numbers look like centimeters to me, but I could be wrong.
You have a barrel that you turn to adjust the jaws of the micrometer.
There are four divisions between the fixed scale numbers,
so it looks like it takes four full turns of the barrel to back off the jaws by one cm.
(Are there 25 numbers on the barrel scale?)
The position of the end of the barrel on the fixed scale gives you the coarse reading.
When the zero on the barrel scale lines up exactly with the line just above the fixed scale,
the end of the barrel should be EXACTLY on one of the fixed scale marks;
either a number or one of the 1/4 cm hash lines.
If this is not true, there is usually a set screw somehow accessible that you can adjust to make this true.
Without going into too much detail here,
you can usually find how far between fixed scale hash marks you have turned the barrel by looking for a line on the barrel scale
that lines up exactly with one of the horizontal numbered lines around the fixed scale cylinder.
You may have to add 0.025, 0.05, or .075 cm to the barrel scale reading
(depending on which of the four turns past a whole cm mark you are on)
to get the right fraction of a cm to add to the coarse reading.

I don't know if I have this "all" right,
but I think there is some sense in it.
(...or maybe not?)

It appears to be a vernier micrometer.

Here are a couple of links that should help:


Gamma

Every mark ,or line , equals .025 thousands . One revolution is .025 . Turn out four revolutions and you will have .100 of an inch .So turn out twice , to 2nd, line is .050 of an inch , keep turning and what ever number you come to add that to .050 . Mic a known diameter . say a 1/4" bolt . Read the mic , it will probubly read .247-.248 thousnths of an inch . Go from there . Take a set of feeler gages , they are marked .005,.007,.025 and so on . Mic them and look at thr reading , Stack them up , add them up , mic them and look at the reading . You'll get it eventually , promise .

Stryped said:

How can I insure I am reading it right and it is accurate?

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It is almost to 1 in I think you are very close 999 and 6/10. There should be a master in the box you need to zero it in so you read 1.0000 loosen the thumb drive to adjust then tighten

greene said:

You can look for a manual online. You'll need to check that your mic is calibrated correctly.
And YouTube usually comes to the rescue to teach us stuff.

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this is reading .375 , or 3/8"

Hello to everyone at Lawn Mower Forum. I'm long time member and this is my 1st post. I'm a machinist by trade for last 45 years and I spent many years teaching Precision Manufacturing at local community college that I attended in the 1970's. The following links are to L.S. Starrett micrometer videos.

: Part 1 - Introduction and terminology.
: Part 2 - How to read a Micrometer
: Part 3 - How to read a Metric Micrometer
: Part 4 - Accuracy, Adjustments, and Maintenance

I showed videos part 1, part 2, & part 4 when I taught and it really helped beginners understand micrometers quickly.
If students wanted they could watch the metric video on their own because we only had inch micrometers.

Good Luck.

All micrometers read an inch at a time. 1-2"; 2-3" etc. Each small segment measures .025"(between the 1-9 numbers); Each large segment with four lines measures one hundred thousandths .100" -.200"; .300-.400 etc. The other scale is tenths, .0001"; .0002" you look to see which two tenth lines are lined up together and add those to the other numbers. Think of a dollar, four quarters and a dime and add them all up to get your reading.
Go onto the Mitutoyo or Starrett tool website and they may have more written details. Like sgkent mentioned, it requires some technique in handling. It's not a c-clamp!

yes, even heat from the hands expands it and makes the readings useless as to a precision tool. Some of the questions asked about crankshaft journals, things like that sometimes people don't realize how small the measurements are that are being measured. A standard sheet of 20 lb printer paper is about .004" thick. A standard mic will read down to .0001 and if you read between the lines, .00001 +/-. Of course that assumes its quality can hold that tolerance and that you have gauge blocks to verify the calibration.

JJBear53 said:

It's not a c-clamp!

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Maybe, maybe not. All depends.