Math Nerd

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Mason Kuettel

Mason Kuettel

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Joined
Oct 25, 2010
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408
Location
Weatherford TX
I'm a math nerd, I embrace it...

My digital calipers measure in both inches (to .001") and milimeters (to .01mm). Which do I use if I want to be more accurate? I'm glad you asked:

1 inch = 2.54cm = 25.4mm
.1 inch = .254cm = 2.54mm
.01 inch = .0254cm = .254mm
.001 inch = .00254cm = .0254mm

Looking at this tells me that .01mm is less than .001in so if I measure to the nearest .01mm (one-hundredth of a mm) I am more accurate than if I measure to .001in (one-thousandth of an inch).

This math nerd will keep his calipers in mm from now on! :biggrin:
 
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Your digital callipers may display smaller measurements but the design is limited to about .001". The display shows to the closest display number on the scale of whatever you selected. If you want to make things to tighter tolerances you need to use a micrometer made for .0001. Keep in mind pens don't need that kind of accuracy. The callipers are enough and the best way to use them is to pick one measurement system and work with it. Errors always creep into things when you are switching back and forth.
 
Curly said:
Your digital callipers may display smaller measurements but the design is limited to about .001". The display shows to the closest display number on the scale of whatever you selected. If you want to make things to tighter tolerances you need to use a micrometer made for .0001. Keep in mind pens don't need that kind of accuracy. The callipers are enough and the best way to use them is to pick one measurement system and work with it. Errors always creep into things when you are switching back and forth.
Click to expand...

The only time I switch from one to the other is if I find an AWOL drill bit and can't figure out what size it is!
 
0.01mm is approximately 0.0004 inches.

Does your digital caliper have a fourth digit on the imperial scale limited to 0 or 5? Mine does. I can measure to the nearest half thousandth. That means that using imperial instead of metric would result in a possible max error of 0.0002" due to rounding in a perfect world.

Now considering that:

A) how you hold the calipers on the piece can easily change the measurement a couple of thousandths

B) all my other sytems and tools work in imperial units

C) the tools that I am using aren't precise enough to make measuring to less than 0.001" meaningful.

I won't be permanently switching my calipers to metric....but it's nice to have the feature for a quick conversion without having to use a calculator when I need to use metric....


Ed
 
parklandturner said:
0.01mm is approximately 0.0004 inches.

Does your digital caliper have a fourth digit on the imperial scale limited to 0 or 5? Mine does. I can measure to the nearest half thousandth. That means that using imperial instead of metric would result in a possible max error of 0.0002" due to rounding in a perfect world.

Now considering that:

A) how you hold the calipers on the piece can easily change the measurement a couple of thousandths

B) all my other sytems and tools work in imperial units

C) the tools that I am using aren't precise enough to make measuring to less than 0.001" meaningful.

I won't be permanently switching my calipers to metric....but it's nice to have the feature for a quick conversion without having to use a calculator when I need to use metric....


Ed
Click to expand...

I have the cheap calipers, only three decimal locations. Guess I could upgrade but, as was stated earlier, you really don't NEED to be more accurate than .001 of an inch!
 
Upgrading to a better calliper will not make much difference. I measure aircraft parts for a living and any dimension with a tolerance of .005 or less is measured with micrometers. Because of the way a calliper relies on operator feel, measurements are not repeatable by different users and even by the same user. Work with the tool you have and only upgrade if you are having issues with it.
 
Yep, Nerd.

Me I open the calipers fit to piece, lock calipers see if new piece fits. If not I remove stock until it does. I dropped my calipers a few weeks ago and busted the gauge. I fretted and fretted and then realized I never used the gauge anyway. What can I say, I was a creative writing major who flunked college algebra not once but twice.
 
parklandturner said:
0.01mm is approximately 0.0004 inches.

Does your digital caliper have a fourth digit on the imperial scale limited to 0 or 5? Mine does. I can measure to the nearest half thousandth. That means that using imperial instead of metric would result in a possible max error of 0.0002" due to rounding in a perfect world.

Now considering that:

A) how you hold the calipers on the piece can easily change the measurement a couple of thousandths

B) all my other sytems and tools work in imperial units

C) the tools that I am using aren't precise enough to make measuring to less than 0.001" meaningful.

I won't be permanently switching my calipers to metric....but it's nice to have the feature for a quick conversion without having to use a calculator when I need to use metric....


Ed
Click to expand...
Actually .0003937
 
Dont worry about it guys... one day all of you will use metric measure units! Unless some upcoming world power forces us all to switch to rice grain thickness on some other stupid unit of measure...

My woodwork teacher and appy shop superintendent both said to me on various occasions: "Its not in which units you measure... Its how accurate you hold your measuring tools while measuring!"
 
Mason Kuettel said:
I'm a math nerd, I embrace it...

My digital calipers measure in both inches (to .001") and milimeters (to .01mm). Which do I use if I want to be more accurate? I'm glad you asked:

1 inch = 2.54cm = 25.4mm
.1 inch = .254cm = 2.54mm
.01 inch = .0254cm = .254mm
.001 inch = .00254cm = .0254mm

Looking at this tells me that .01mm is less than .001in so if I measure to the nearest .01mm (one-hundredth of a mm) I am more accurate than if I measure to .001in (one-thousandth of an inch).

This math nerd will keep his calipers in mm from now on! :biggrin:
Click to expand...
I suspect very strongly that you'll never notice the difference and since most of your customers won't be carrying a calipher and probably can't detect .001 in or .01mm with their naked eye they probably won't notice either. In that case I recommend that you use which ever scale churns your butter, floats your boat or makes your shoes feel most comfortable.:biggrin:
 
The (reliable) accuracy of you measurement is limited to the accuracy of your calipers.

If they are accurate to .01 mm then that is as accurately, it to .991 inch then that is the accuracy you can reliably achieve regardless of the mm reading.

Metric measurements are actually easier to use since fractional and standard are the same as divisions of ten at any size.
 
Wow what a conversation. As someone mentioned before how do you hold your calipers. The tool is only as accurate as the user. Someone once told me I needed a certain scope for my rifle that it was accurate for 1000 yards. I said why spend three times the money when I'm only good at 300yards. I guess that holds true for anything you do. If the tollerance needs to be tighter than we need to practice more but I don't want to take away the fun with over kill. Thanks
 
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