Lead 'test blocks' for Brinell test

[Rio Grande]

I work in a shop that does a lot of Brinell and Rockwell hardness testing, and have become very interested in testing lead, 5 to 35 Brinell accurately. I have studied this and am ready to begin testing, except for one thing.
For the harder metals we have certified test blocks, to verify the testing machines accuracy.
But for such low Brinell #'s as I want to test I can find no test blocks.
'Pure' lead is Brinell 5...but I need something verifiably in the ranges I will be checking.
Any source of 'test blocks'? Or is there any other substances that would unfailingly have a known hardness in that range?
Without 'proof' and verification, all tests are worthless.

[Bob Krack]

For the harder metals we have certified test blocks, to verify the testing machines accuracy.
But for such low Brinell #'s as I want to test I can find no test blocks.
'Pure' lead is Brinell 5...but I need something verifiably in the ranges I will be checking.

http://www.rotometals.com/Bullet-Casting-Alloys-s/5.htm, one of our sponsors here, offers 99.9% pure lead and I assume certification would be available.

Bob

[Calamity Jake]

Yap you can try rotometals as Bob says or if you know a bench rest shooter that makes his own jacketed bullets he will have lead wire for making cores, this lead wire is certifiable and he may have the certs, see if you can get a 1/2-3/4 pound sample, you can use it to qualify the hardness tester.
The test piece needs to be a minmum 1/2" thick and fairly flat on both sides.

[KYCaster]

You might try pure Tin and Bismuth. I don't recall the exact hardness, but they should do what you want.

Pb, Sn and Bi should cover both ends and the middle of the range you're interested in.

Jerry

[Bill*]

i think he's asking for a source of test material "verifiably in the ranges I will be checking" such as BHN 12 or 15 or whatever.

[KYCaster]

i think he's asking for a source of test material "verifiably in the ranges I will be checking" such as BHN 12 or 15 or whatever.

Exactly. Pure metals are as consistent and varifiable as it gets.

Like I said earlier, I don't recall the exact figures, but the hardness of pure Sn is near the middle of the desired range and Bi is near the top.

Along with Pb, that provides three data points. Is there something else I'm missing?

Jerry

[Rio Grande]

Exactly. Pure metals are as consistent and varifiable as it gets.

Like I said earlier, I don't recall the exact figures, but the hardness of pure Sn is near the middle of the desired range and Bi is near the top.

Along with Pb, that provides three data points. Is there something else I'm missing?

Jerry

That's excellent. Pure Tin and Bismuth, if 'in the middle of the desired range...and at the top' seems a perfect solution.
I'll check and try to find out the hardness of those.
Thanks.
Lots of knowledgeable and helpful people here.

By the way, with my method (12.7 mm ball and 100kgf) I'm getting good numbers at the low, verifiable pure lead test, but my tests of various boolits from here and there show what I suspect to be too much hardness, contrary to what you might think... and I'm thinking an error in measurement (force) might be cumulative, so that the error increases as does the hardness.

[Doc Highwall]

One way to eliminate the force error is to use your steel ball with a known sample of pure lead and your sample in a vise making a dent in both simultaneously.