Lead hardness. There is no way...

[Rio Grande]

...to verify accuracy of hardness testers without certified known lead hardness test blocks.
You can compare, but actual hardness you will not know.
Any and all hardness testing apparatus are worthless without certified test blocks.

[Chicken Thief]

Same as almost anything else!
But:
Pure lead is no more than 5 BHN
Pure Tin is no more than 21 BHN
Pure Zink is no more than 45 BHN
Pure (hard) Copper is no more than 72 BHN

So you might be able to compare actual measurements to your readings and take the deviance into account?

http://www.zianet.com/ebear/metal/hardness.html

[JonB_in_Glencoe]

I guess that depends on how accurate you need to be ?

with my Lee tester,
I get 5 or 6 with some known soft lead
AND
I get 10 to 12 with straight air cooled COWW
AND
I get 18 or 19 from my known Linotype

Accuracy...
If I can get within ±1 BHN, that's good enough for my casting.
with the readings I've gotten, I am pretty sure I am there.

[phaessler]

Sounds like someone is trying to justify not owning a hardness tester,,,,, just kidding .

But yes its all in a relative world, and once know by any standard (stick-on, COWW, isotope, LINO) it sure does help pick where you want to be for usefullness.
Pete

[Walter Laich]

I know that when I get ~5-6 Bn on air cooled and ~12-15 Bn on water cooled the water cooled ones are going to be harder. That's good enough for me, others may need more precision.

walt

[btroj]

Technically what he said is true.

I don't care, however. My tested need not give me a purely accurate number, I use it to give me a relative hardness number.

I don't care if my tester says it is 9.5 and it actually is 10.5. I just want to know that one batch to the next 10.5 is 10.5.

Relative hardness and consistent results are far more than the overall pure accuracy of the hardness. This is a hobby, not industry. I am not certifying my results.

[GP100man]

Technically what he said is true.

I don't care, however. My tested need not give me a purely accurate number, I use it to give me a relative hardness number.

I don't care if my tester says it is 9.5 and it actually is 10.5. I just want to know that one batch to the next 10.5 is 10.5.

Relative hardness and consistent results are far more than the overall pure accuracy of the hardness. This is a hobby, not industry. I am not certifying my results.

I use it to blend alloys for a consistent batch to batch of alloy.
As all has mentioned for our purposes the tools offered for boolit casting are "close nuff" .
In the swapping section there is a service offered to test alloys.

http://castboolits.gunloads.com/showthread.php?179066-Lead-analyzing-service-Part-2

[Junior1942]

Technically what he said is true.

I don't care, however. My tested need not give me a purely accurate number, I use it to give me a relative hardness number.

I don't care if my tester says it is 9.5 and it actually is 10.5. I just want to know that one batch to the next 10.5 is 10.5.

Relative hardness and consistent results are far more than the overall pure accuracy of the hardness. This is a hobby, not industry. I am not certifying my results.+1 on all of that.

[Maven]

If you haven't seen this before, look at the late Ken Mollohan's work with artists' pencils: http://www.google.com/cse?cx=001951264366462437169%3Aggn3vg-bjum&ie=UTF-8&q=checking+alloy+hardness+with+artists+pencils&sa=Search

Btw, I found this using Montana Charlie's Google Custom Search-Cast Boolits

[Jon]

The engineering answer is does it matter?

If it's close enough to get you what you want, then it's good enough.

[montana_charlie]

Any and all hardness testing apparatus are worthless without certified test blocks.
If you paid umpty-thousand dollars for a lab-grade Brinell tester, would you still need the certified test blocks?

CM

[lavenatti]

I'd be a lot more worried about my powder scale than my hardness tester.

The same rule applies.

Anybody use a calibrated weight or do you just trust it to be correct after you zero it?

[runfiverun]

i have 3 two place scales and one 3 place scale.
they all disagree by @.01 on just about everything i weigh on them.
i'm cool with that.
a half tenth either way is close nuff on powder too.

[troyboy]

Absolutely correct. Ballpark is close enough. It is just a guideline.

[res45]

All I know is once I got my hands on a Lee tester all the various alloy I use and the bullets I tested all came out pretty darn close to what I though they should be. Never had any issues related to hardness and pressure based on those assumptions.

[mdi]

...to verify accuracy of hardness testers without certified known lead hardness test blocks.
You can compare, but actual hardness you will not know.
Any and all hardness testing apparatus are worthless without certified test blocks.
And your point being???