The Old Argument: Actual Brinell Measurement/Hardness

[P Flados]

BHN is a direct measurement of the properties of the material.

I made my own tester and it functioned well enough. The principle is simple enough and the results are what they are.

Pure lead may be an exception, but in general I would be much less sure that any given "certified alloy" has a specific BHN. Material properties involve both the chemical composition and things like grain structure. Also "trace" amounts of materials other than the primary constituents can sometimes affect results.

So, be "happy" if you have gotten better at reducing uncertainties in your measurements. However, do not expect your measurements to tell you much more than the hardness.

[mehavey]

Of possible interest:
Test results back today of RotoMetals 30:1

AST (Applied Tech Services, Marietta, GA) BHN 5.8
This a $200 test and (for me ) well worth it.
NOTE: Compare to LEE Tests/Post#1 and Post #8


They're giving me another quote for an even more precise test,
which I might take them up on, just on general principles.

[dtknowles]

Of possible interest:
Test results back today of RotoMetals 30:1

Attachment 323494
NOTE: Compare to LEE Test/Post#1
This a $200 test and (for me ) worth it.

They're giving me another quote for an even more precise test,
which I might take them up on, just on general principles.

Thank you sir.

Tim

[P Flados]

I remember trying to make a ~50# batch of medium hard alloy using starting out with near pure and adding in junk commercial hard cast, and some high tin stuff I had. I would add some hard stuff, poor an ingot and test it. Then add some more hard stuff. It remember that it took a lot more hard stuff to get above 6 than I expected. I was originally going for ~10, but stopped closer to 8.

I have seen what RotoMetals says for the BHN of the various lead - tin alloys they sell. Your test results are pretty far off compared to their number.

My guess it that either their info is just wrong, or it is based on some batches that had small amounts of "extra stuff" in them that pushed up the hardness.

[mehavey]

I have seen what RotoMetals says for the BHN of the various lead - tin alloys they sell.
Your test results are pretty far off compared to their number.

My guess it that either their info is just wrong, or it is based on some batches that had
small amounts of "extra stuff" in them that pushed up the hardness.

I started testing RM's 30-1 a decade ago, multiple batch orders over the years.
The results have never varied during all that time/all those batches: 5.7- 6.0

AST's lab test on the latest batch/sample verify those results: 5.8 in this case.
(BTW, no complaints at all. I deliberately cast & shoot for the hardness as it actually is.)

I believe what is happening is that "accepted BHN of 9" has been promulgated by
so many people, so many sources, so much internet lore that it has become
"accepted fact" -- notwithstanding no actual re-testing.

But I'm still going to have AST re-test with finer calibration standard.
We owe that to the everybody involved.



There's an old wry saying in physics:
When the data disagrees with the theory,
so much the worse for the data

[Recycled bullet]

Well thought out-- never mind the firestorm. The thing that amazes me sometimes is how uptight people get about the bullet hardness. I have a bar of Lyman #2 I keep around for testing mystery alloy. I want my pistol bullets to be softer and my rifle bullets to be at least as hard. When I get my hands on mystery alloy I squeeze a ball bearing between the #2 and the mystery piece in my vice. I just compare the diameters of the indents-- the softer one will be larger-- to decide what to do with the alloy.

That's a really good idea

[KenH]

Of possible interest:
Test results back today of RotoMetals 30:1

AST (Applied Tech Services, Marietta, GA) BHN 5.8
This a $200 test and (for me ) well worth it.
NOTE: Compare to LEE Tests/Post#1 and Post #8


They're giving me another quote for an even more precise test,
which I might take them up on, just on general principles.

I think you've settle the value of 30-1 RM just fine. Thank you for spending the $200 for the test, not sure it's really worthwhile to spend even more money to confirm what you've already found out. I find it interesting that RM says "the Brinell Hardness Number of 1 to 30 Alloy is about 9.". Do they not test?

[Willie T]

I started testing RM's 30-1 a decade ago, multiple batch orders over the years.
The results have never varied during all that time/all those batches: 5.7- 6.0

AST's lab test on the latest batch/sample verify those results: 5.8 in this case.
(BTW, no complaints at all. I deliberately cast & shoot for the hardness as it actually is.)

I believe what is happening is that "accepted BHN of 9" has been promulgated by
so many people, so many sources, so much internet lore that it has become
"accepted fact" -- notwithstanding no actual re-testing.

But I'm still going to have AST re-test with finer calibration standard.
We owe that to the everybody involved.



There's an old wry saying in physics:
When the data disagrees with the theory,
so much the worse for the data

Out of curiosity did you have the content of the alloy tested? For me that would be the final piece of the puzzle. Was the alloy actually 30/1 lead/tin? I own the Lee tester. I never use the hardness tester. I make my own purpose specific alloys and have never purchased any ready made alloys. I’ve done a lot of experiments to determine what I can do with various alloys. I can easily repeat the alloys. Actual content of the alloy is what I’ve always been interested to know. I never paid much attention to bhn. That said, Lyman No2 is a good example of BHN driving the boat. Described as 90/5/5, Lyman gives recipes to alloy No2 with either clip on wheel weights or Linotype as the base of the alloy. The recipes approximate the same hardness but their composition is quite different. Before someone gets wrapped around the axle about it having to be 90/5/5, it is Lyman’s alloy and Lyman’s recipes. Obviously Lyman No2 is about how to generate an easy casting alloy of a given BHN, rather than content.

[mehavey]

I have been purchasing certified alloys from Rotometals since 2012.
They have been absolutely consistent in both service and product.

So too have their alloys (90/5/5 Lyman #2, and 30-1) "Lee" tested as well:
#2 at Brinell 14.9-15.0; and 5.7-6.0 for 30-1.

Today ATS/Marietta came back w/ the extended ASTM E10-23 test on the 30-1 Alloy Ingot:
5.88 HBW(tungsten) indenter

[Willie T]

I have been purchasing certified alloys from Rotometals since 2012.
They have been absolutely consistent in both service and product.

So too have their alloys (90/5/5 Lyman #2, and 30-1) "Lee" tested as well:
#2 at Brinell 14.9-15.0; and 5.7-6.0 for 30-1.

Today ATS/Marietta came back w/ the extended ASTM E10-23 test on the 30-1 Alloy Ingot:
5.88 HBW(tungsten) indenter

Have you had the alloys tested for content? What you had tested consistently came back with pretty close numbers for hardness. Have you verified that it is in fact 96.8% lead and 3.2% tin? Testing the same batch of alloy you had tested for bhn for content would lend credence to your assertion of the true hardness of 30:1.

[mehavey]

I have no (zero) doubt that RotoMetals is producing/selling accurate/virgin alloys.

But if you really doubt that . . . .

[Willie T]

I have no (zero) doubt that RotoMetals is producing/selling accurate/virgin alloys.

But if you really doubt that . . . .

I’m not the one making the big deal about testing methods. I’m not trying to besmirch RotoMetals either. I have never bought casting alloys from them. I mix my own. I have had some of my own alloys tested for content, even though I completely trust myself. I am well versed in generating data through R&D. The first rule in testing something is to verify what you are testing if you want to compile reliable data points. Maybe I didn’t follow what you were trying to establish by having your alloy independently tested for hardness twice. Were you doubting Lee’s claims about their hardness tester or trying to determine the actual bhn of 30:1?
Willie

[dtknowles]

I’m not the one making the big deal about testing methods. I’m not trying to besmirch RotoMetals either. I have never bought casting alloys from them. I mix my own. I have had some of my own alloys tested for content, even though I completely trust myself. I am well versed in generating data through R&D. The first rule in testing something is to verify what you are testing if you want to compile reliable data points. Maybe I didn’t follow what you were trying to establish by having your alloy independently tested for hardness twice. Were you doubting Lee’s claims about their hardness tester or trying to determine the actual bhn of 30:1?
Willie

I think the issue is that common knowledge has 30:1 being considered harder than it actually is, should be 6 BHN but often thought to be closer to 9 BHN. In a way the hardness does not matter, if the application calls for 30:1 just make or buy 30:1 and don't worry about the hardness. I think me and my Lee tester are close enough, but hardness will not tell you actual composition. I use a lot of range scrap and wheel weights so while I can test for hardness, I don't know actual composition. I don't use 30:1 for anything so I don't have a dog in this fight but if I have an alloy with a BHN of 16 is it 2% tin and 6% antimony or is it 5% tin and 5% antimony. This can become important if you want to formulate a softer alloy using this alloy as a component. One you mix it 50/50 with pure you get 1% tin and 3 percent antimony and the other you get 2.5% tin and 2.5% antimony. The later will probably be easier to cast good bullets and will be just as hard and more ductile.

Tim

[mehavey]

If the Gentle Reader wants to see the origin of this discussion, see these posts in order:

https://www.marlinowners.com/threads...6/post-8839428
https://www.marlinowners.com/threads...6/post-8839437
https://www.marlinowners.com/threads...6/post-8839472

(I think it was the opening line of the 3rd post
"...Sounds like someone knows more than the industry engineers that set the standards.
Maybe all my college engineering professors did not know what they were teaching was wrong..."
...that lit the fire.

But in reality, knowing the actual hardness of common lead-tin alloys -- which are unique in being almost immediately age-stable -- is of no small importance... especially if the "accepted internet lore" has them as much or more than 50% harder than they actually are.


Naturally, powder-coating has largely thrown all that out the window lately by making even the softest bullets effectively "polyester/epoxy-patched," and able to be pushed really hard.
https://castboolits.gunloads.com/sho...=1#post5592837
https://castboolits.gunloads.com/sho...=1#post5001471

... but there's always those pesky bore riders that don't like the extra PC girth along those long noses.

[charlie b]

... but there's always those pesky bore riders that don't like the extra PC girth along those long noses.

But for those of us who use them with PC there are nicely made nose size bushings from NOE

[mehavey]

I'm going have to probably break down and look at those nose bushings....

[tnflyfisher]

I have the Lee hardness tester and Veral Smith's which I like a lot better. Smith's is quick and easy to get repeated results. I have trouble getting a consistent read from the Lee scope. Smith still has a few testers available at lbtmolds.com although he is out of business for molds. His shop completely burned down last Christmas eve. Sorry to see all that end, I like his molds and products.

[mehavey]

I have trouble getting a consistent read from the Lee scope.

Forget the Scope (for now).
Just put it on your printer/scanner at 9600 px/in and reading the indent diameter becomes a no-brainer.


(Certified RotoMetals 30-1)

[Chill Wills]

mehavey
Question....
With your system, does Roto Metals 30-1 read as a BHN of 5.7????

[mehavey]

5.7 - 5.9 BHN (Rotometals * )
Not only the Lee tester/scanner reading the impression -- same readings over multiple samples, multiple years, three different testers. **
....but the Materials Testing Lab I sent the 30-1 ingot to so as to settle the debate back 5-6 weeks ago.

Applied Technical Services, Marietta GA ***
IAW ASTM E1479-16, ASTM E1621-22, and ASTM E10-23

--- Pb - Sn - Si
% 96.4 3.6 0.1 (* effectively 29.9-to-1.1)
Test 1: BHN 5.8 1st Test w/ Basic reference
Test 2: BHN 5.88 2nd test w/ Precision reference

There's never really been any issue in my mind as to actual hardness of the classic 30-1 alloy, and good use of it over those years.
Perfectly good performance (and great expansion as you might expect) in moderate/traditional load ranges.
I've loaded it for what it was in actuality.

** Tidbit from several years ago:
https://castboolits.gunloads.com/sho...1#post1852750]

*** Good people. I recommend them,