Digital Vernier Hardness Measuring.

[303Guy]

Is there any one else using a digital vernier to measure boolit hardness?

I place the boolit between the jaws (the sharp bit), zero the vernier then squeezebetween thumb and finger. The indent is then read off the digital scale. Dead soft lead gives me about 0.35mm/.014" and lini gives me zero - too hard to measure that way. My lead pipe-tin/copper alloy gives me a usable measure of 0.13mm/.005" and WW gives me 0.2mm/.008". These are quite repeatable (the WW needs to be confirmed). I can follow the age hardening over hours and days with this method. I have no idea what the actual BHN for my alloy is. I can also detect harder and softer zones on the same boolit. It's useful to me for comparing my alloys. I did anneal some boolits and measure the resulting 'softness' but have forgotten and lost the results. There was a change. I also found that heat treating only served to harden my alloy quicker. After a few hours there was no difference. That's an alloy thing but it serves to indicate the usefulness of my system.

[gray wolf]

Just a guess here--- but I think you are going to mess up your caliper.
I don't think a precision tool should be stressed like that.

[onondaga]

I think you will mess up your caliper too.

There are some pretty novel methods for testing bullet alloys. The lead pencil set method posted recently looks pretty good if you aren't willing to buy a decent specific tool.
Your caliper method will likely cost you a caliper soon. Put it away first and try pencils. Maybe save up for a tool. I have the Lee Hardness Tester. It works well for me and was worth the cost to me. I have 2 calipers that were each higher in cost than the Lee tool.

Gary

[Doc Highwall]

Yes the calipers will deflect some.

[John Boy]

... what the other posters said - not a good idea using the calibers.
Never heard calipers called a vernier before - but that's them!

[rmcc]

Vernier calipers WILL lose their index for zero doing this !! Some are better crafted and will keep their calibration longer but none are made to do this. I have a messed up Mitoyu I will send you if you want to save your other vernier.

Rich

[Doc Highwall]

Vernier calipers are what they were first called when they came out and had no dial on them. They were invented by a French man named Perry Verniere and you read them by matching up lines that will read to .001". This was the system that was used on graduated rear sights that we call a Vernier Tang sights that have lines that line up every .010" which is pretty close to one minute of angle for most rifles. Here is one that reads .560" The same principal as is on your micrometers that read in .0001".

[MikeS]

Vernier calipers are what they were first called when they came out and had no dial on them. They were invented by a French man named Perry Verniere and you read them by matching up lines that will read to .001". This was the system that was used on graduated rear sights that we call a Vernier Tang sights that have lines that line up every .010" which is pretty close to one minute of angle for most rifles. Here is one that reads .560" The same principal as is on your micrometers that read in .0001".

I have a vernier caliper that I've had maybe 40 years, and I'm pretty sure it's older than I am. It's made by a company called MZB and it's marked "Made in Germany - Western Zone" so they're from before they officially named West Germany! The only problem with them is that my eyes can't read the small lines anymore!

One thing about these old calipers is that when all the dial calipers, and electronic calipers have bit the dust, these will still work, IF anyone still knows how to read them! Below is that Vernier Caliper set to .452 (at least it should be, my bad eyes can't verify that, but I measured a boolit that's .452 on my digital calipers, and my micrometer, so it SHOULD be set to .452 although I doubt anyone can tell by the photo either!).


http://castboolits.gunloads.com/imagehosting/thum_177914d8b91fa9c84c.jpg (http://castboolits.gunloads.com/vbimghost.php?do=displayimg&imgid=300)

[Doc Highwall]

Mike that is why the made magnifying glass's for I have been using them for years. Vernier calipers have nothing to get out of whack except our eyes.

[bowfin]

I had a pair of all three types (digital, dial, and vernier) when I did Tool & Die. One day, a Quality Control Inspector came through the toolroom and wanted to measure something, so I gave her my dial calipers to use. She turned up her nose and said "I want the other kind". Quick as a wink, I whipped out the verniers and held them out. She turned around and walked away.

Yeah, a little bit (lot) of being a smart@ss, but chances are she wouldn't have zeroed out the digital ones before measuring anyhow.

Anyone else ever hear vernier calipers called "very near" calipers?

[R.M.]

Yup, we called them "Very Near's" all the time.

[Simonpie]

I've always had a perverse urge to build a vernier clock. Just one hand in the form of a big disc that moves at the same speed ar the hour hand. Around the edge of the disc are marks that line up at each minute (or 5 minutes if you're making it simple). It would take a little effort to read the time, but could make a nice shop decoration.

On the original thread, as for damaging calipers, if the load to the bullet is directed straight through the jaws instead of pushing on the thumbscrew or body, I can't imagine any damage to them. They won't be loaded in bending. Certainly the lead won't ding the stainless jaws.

[Von Gruff]

On the original thread, as for damaging calipers, if the load to the bullet is directed straight through the jaws instead of pushing on the thumbscrew or body, I can't imagine any damage to them. They won't be loaded in bending. Certainly the lead won't ding the stainless jaws.

That was my read on what 303guy meant as well Simon and I can see the comparative use although getting the same thumb - finger pressure either side of the jaws may take a bit of practice. 303guy says he has repeatable results.

Von Gruff.

[Pepe Ray]

Siemanpie;
I thought that that was what 303 Guy meant--
"--squeeze between thumb and finger".
Right?? Is'nt that what he said,?
Maybe I can't read, or comprehend.
Pepe Ray

[MikeS]

Mike that is why the made magnifying glass's for I have been using them for years. Vernier calipers have nothing to get out of whack except our eyes.

I agree with that thought! a few weeks ago I bought a 'CEN-TECH' digital calipers from Harbor Freight, and while they only cost $11.00 I think (going from memory which lately isn't a really good idea) it was a total waste of time. Measuring the exact same boolit that I did for the picture of the verniers above which was also measured by 2 different mics (one digital, the other semi digital, both mechanical, not electrical) and the digital calipers shows it as .449 when everything else I measure it with says .452! If this measurement is off, how can I trust it for any others? I just hope I have better luck with the dutch oven I bought there on the same day!

[303Guy]

Yup. That's what I meant!:mrgreen:
And I'm talking one of those $11 types. I did get mine to read a lot more accurately by fiddling with the slide pressure adjustments. The jaws were not parallel before that. It does give quite consistant differences though. And yes, I did call a digital caliper a 'vernier'. Heck, I remember when dial calipers became the rage! And vernier calipers do wear out. My original one no longer has parallel jaws but I once used it to bore a hole so precisely that a ground pin would push in, hold for a few seconds then push out from the air trapped inside.

Anyway, I appreciate all the humour.:mrgreen::drinks:

I am contemplating mounting a DIGITAL CALIPER in a device that can apply a known constant force across the jaws but the trouble is, it won't be able to relate too well to the units used by everyone else. The next idea would be to affix a flat to one jaw and a half ball to the other so that I can measure the indentation depth which I can then convert to BHN.