Please read and understand the entire post before responding. My problem here is very pointed, and has nothing to do with the Brinel hardness of pure lead!
I greatly enjoy using the alloy calculator I downloaded from this website, but there is either a mistake or I don't understand something. ??
The Rotometals formula used in the calculator is: 8.60 + ( 0.29 * %Tin ) + ( 0.92 * %Antimony)
This was copied directly from the spreadsheet calculator.
formula from Rotometals website: 8.60 (Antimonial Lead) + ( 0.29 * Tin ) + ( 0.92 * Antimony )
The value of Pure Lead in the calculator is listed as "5". I have no problem with that number for pure lead, as that is not my problem here. As can be seen from the formula on the Rotometals website, the BHN of 8.6 is for their Antimonal Lead, not Pure Lead. The Rotometals Antimonal Lead already has 3 to 5% antimony in it. So, should the formula used in the calculator for our purposes not use the value of 5 instead of 8.6 to start the formula, since the base metal intended for the formula for our use is pure lead, and not antimonal lead? I checked, in the fx bar of the spreadsheet, and the actual formula as entered does use the value of 8.6 as already described.
Or, I am missing something? The reference to the Antimonal Lead in the formula (in parentheses) was copied directly from Rotometals website. It is their reference, as I did not edit that into the formula.
This formula description is on the first page of Rotometals "Bullet Casting Alloys" page, just under a picture of a boolit and the American Flag. I would give a link, but I fear running afoul of the "links rule".
Confused or not, something does not seem right to me. But, I greatly enjoy using the calculator. Thanks to any and all who have provided this for us. I just cannot remember who posted this for us.
Thanks,
Bob