# Vernier Scale



## T-Man (May 16, 2008)

To date, I have use calipers to measure screw and bolt lengths or compare sizes to each other. Recently I have noticed in prewar axles and armatures may be listed as a fraction of an inch. So I went online to figure out how to use a caliper. After all I own a nice plastic one, even three They were very inexpensive. So here it goes

The first scale shows an inch with divisions. Mine has 16 so 1/16 =.0625 inches per division.
Now the second scale has 8 divisions and it is printed that they are 1/128 inches = .0078125 inches per division.

Next I measured an axle The first scale read 2 + divisions. 2x.0625 =.125
On the second scale the 6th division lined up correctly to the first scale. So 6X.0078125 =-046875
To get the final measurement in inches add them together .125 + .046875 = .171875

Nothing is ever perfect but according to the parts supplier the axle is .180 inches so I am .0072 inches off.


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## T-Man (May 16, 2008)

Ok a bonus. The calipers also do metric. It is a little easier. I thought so.
We start with 1 cm with 10 divisions which is 1mm. I measured 4+ = 4mm
The second scale has 20 divisions that are .05mm each but the scale reads 10.
The 5.5 division aligned to the first scale is set for an actual read of .55mm or 11 divisions X .05.
Then add them up 4mm+.55MM =4.55mm.

Both systems of measurement are on the same caliper.
4.55mm/25.4=.179133 inches


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## gunrunnerjohn (Nov 10, 2010)

Treat yourself to a decent caliper, I use the Shars 6" Dual Reading Inch/Metric model.


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## T-Man (May 16, 2008)

Where's the fun in that! It would be easier to use and more accurate.


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## gunrunnerjohn (Nov 10, 2010)

T-Man said:


> Where's the fun in that! It would be easier to use and more accurate.


We all find our fun where we can. When I get a measurement wrong and screw something up, normally I don't view it as all that much fun!


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## Lemonhawk (Sep 24, 2013)

Your reading the Vernier correctly. How accurate your Vernier caliper is may be the problem or its just a manufacturing tolerance. Check to see what the caliper reads when the jaws are closed, that is also a big error source. I have a really nice electronic one that reads directly in either inches or mm and I have a cheap dial caliper like GRJ (mine is much cheaper in plastic). The advantage of John's is that it does not use batteries, and my electronic one is sometimes dead when I need it! I'm sure that's why John uses the one he has over a gee-whiz electronic one. If you do get an electronic one make sure it has auto-off and the case does not constantly press the on button!


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## MichaelE (Mar 7, 2018)

gunrunnerjohn said:


> Treat yourself to a decent caliper, I use the Shars 6" Dual Reading Inch/Metric model.
> View attachment 565798
> View attachment 565799


I have an AccuPro. Looks exactly the same except the name on the dial. Even the box is nearly identical except slightly more compact and not blow-molded.


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## gunrunnerjohn (Nov 10, 2010)

I have a couple of battery powered ones, and Lemonhawk is right on, they batteries are always dead when you need them!  I love the idea of the electronic ones, just not the practicality.

I also have a Lyman SAE only dial caliper, that was used when I was reloading. When I moved I sold all my reloading stuff, just kept the calipers.


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## Lehigh74 (Sep 25, 2015)

I have a Sears Craftsman that I got many years ago. I’m not planning to get a dial type since I don’t use it very often and I’m used to using the scales. Reminds me of the olden days when I used a slide rule. The only problem I have with it is I have to have it in just the right light to see where the lines meet to get that last digit.


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## gunrunnerjohn (Nov 10, 2010)

Trying to see the fine grads is why I have the dial versions. Yes, I still have one of those Bob, but it's buried in the bottom of my roll-around toolbox somewhere!


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## Lemonhawk (Sep 24, 2013)

Being nearsighted, seeing close up just meant taking off my glasses and looking at things about 2 inches in front of my face. After doing this for a 76 years, I'm not looking forwarded to loosing this capability with cataract surgery. So far I'm still hanging in there!


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## gunrunnerjohn (Nov 10, 2010)

I used to do the same thing, but a few years ago after cataract surgery, that all changed. Of course, now I can drive without glasses, my distance vision is excellent for the first time in my life!


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## Lemonhawk (Sep 24, 2013)

My brother had cataract surgery,. Said it was the only time Doctors really improved his day to day living!


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## gunrunnerjohn (Nov 10, 2010)

It was a mixed blessing for me. Now I know where all the pairs of reading glasses are, and I keep them in various strengths, depending on what task I'm doing. However, my night vision is vastly improved, I was starting to not like driving at night as I couldn't see that well at times. My first selection criteria for a new car was HID headlights. Now driving is no sweat, but seeing up close on the workbench is more of a challenge.


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