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Drill bit size gauge

johninct

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Dec 21, 2010
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Is there a quality difference between stainless steel drill bit size gauges that are like $6.00 on Ebay or if I was to buy it somewhere else? I know I can trust the 50 year old one I have but would like another. I just don't want one where the holes wear out after awhile.
 
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larry_g

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oregon
Personally I don't use them. I find a caliper much quicker. They are all going to wear unless tool steel which will just wear slower. Do they have gauge's that cover all the letter, number, fractional, and metric that may be in the unknown pile?

lg
no neat sig line
 

pstemari

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There's a huge difference between a Starrett drill gage, which is hardened and ground, and the cheap stamped steel gages. You'd have a very hard time wearing out the Starrett. It's 0.088" thick.

You can try and use calipers, but there's some number drill sizes that you'll have a very hard time distinguishing with calipers. A mic will work better.

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larry_g

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You can try and use calipers, but there's some number drill sizes that you'll have a very hard time distinguishing with calipers. A mic will work better.

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If your needing the precision that a micrometer will give you then the holes your making are probably of a tolerance beyond what a drill bit will deliver.

And yes there are Metric drill bits all over the world. Remember that the US is one of the few country's still holding onto the imperial system.

lg
no neat sig line
 
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OccupantRJ

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If your needing the precision that a micrometer will give you then the holes your making are probably of a tolerance beyond what a drill bit will deliver.

And yes there are Metric drill bits all over the world. Remember that the US is one of the few country's still holding onto the imperial system.

lg
no neat sig line

I agree. I have never had an issue using a caliper to measure drills for the last 45 years in my work.
 

pstemari

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If your needing the precision that a micrometer will give you then the holes your making are probably of a tolerance beyond what a drill bit will deliver....

You will have a very hard time distinguishing a #34 from a #35 or #45 from a #46 without a good drill gage or micrometer. Dial calipers aren't able to get a consistent reading to distinguish a 0.001" difference. There's too much flex in the jaws.

Been there, done that, bought the T-shirt.

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larry_g

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oregon
You will have a very hard time distinguishing a #34 from a #35 or #45 from a #46 without a good drill gage or micrometer. Dial calipers aren't able to get a consistent reading to distinguish a 0.001" difference. There's too much flex in the jaws.

Been there, done that, bought the T-shirt.

Sent from my Pixel XL using Tapatalk

When a drill bit in that size range has a +.004/-.001 expected hole size, https://www.engineersedge.com/manufacturing/drill-mechanical-tolerances.htm, It really doesn't matter if your goal is a precision hole. Twist drills are just not a precision cutter.

And if the OP is considering a $6 gauge he is not working to any tolerance that a machinist would be..

Hell for all we know the OP is a carpenter.

lg
no neat sig line
 

WhataTool

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Sep 8, 2015
Messages
466
You will have a very hard time distinguishing a #34 from a #35 or #45 from a #46 without a good drill gage or micrometer. Dial calipers aren't able to get a consistent reading to distinguish a 0.001" difference. There's too much flex in the jaws.

Been there, done that, bought the T-shirt.

Sent from my Pixel XL using Tapatalk

You're missing the point here. If calipers are not offering enough accuracy (.001" as you say) a drill bit is the wrong tool to be using in the first place. You should be drilling a hole or lathe cutting a hole to size then finish reaming to the final diameter.

If your final hole is created with something as simple as a twist drill, calipers are plenty dependable.
 

davethorik

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Sep 14, 2013
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Location
Norka, Ohio
Dial calipers aren't able to get a consistent reading to distinguish a 0.001" difference. There's too much flex in the jaws.

Been there, done that, bought the T-shirt.

Sent from my Pixel XL using Tapatalk

Absolutely false. You need to practice using calipers more.
 
OP
J

johninct

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Dec 21, 2010
Messages
2,595
I just want to clarify. I have one that is 60-70 years old or more. I just need another. I find it very useful to quickly measure a bolt or drill bit. I just don't want one that will quickly get reamed by a bolt or drill bit.
 
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