Converting Bhn to Alloy Ratios - Not On the Normal Tables

[John Boy]

Is there - What is ... the formula to convert a Brinell Hardness number to a given 1:X alloy ratio of Sn and Pb?
Here is the best Brinell Hardness Table from Fr Frog's website ... http://www.frfrogspad.com/miscellm.htm#Brinell

I have never seen a table with the alloy ratios greater than 1:40. If one wants to determine the corresponding Bhn to say, 1:11 or 1:15 or even 1:50, etc ... what is the formula?

I've done my homework looking and have not been able to determine what the conversion formula is. There has to be such a formula otherwise 1:30 would not be designated with a Bhn of 9.0 as an example

RotoMetals has this formula for adding tin and antimony to obtain harder alloys but have not found the formula starting with dead soft PB, then adding Sn to derive the Bhn number

Basic Rules for Harding Lead-
For every 1% additional tin, Brinell hardness increases 0.3.
For every 1% additional antimony, Brinell hardness increases 0.9.
For a simple equation,
Brinell = 8.60 + ( 0.29 * Tin ) + ( 0.92 * Antimony )

[fryboy]

umm i dont know a formula,i know i did test a bunch of alloys,ingots,and boolits when i first got me lee dinger (tester) some surprised me i,i did scribble a few of them down ,the hardest thing from my stash so far was a ingot of pewter with a .044 ding (27.2 BHN) one of the surprises was a old piece of lino still intact .058 ( 15.4 ) i found that my lyman recipe for #2 is harder when made with lino than with ww/tin ,my ww's ( fresh) run .070 +/- .004,when i'm not looking for the sheet i wrote it all down on i'll find it lolz

[alfloyd]

I have a excel work sheet that will give you any ratio you want.
It is by Jess Dressler, with some mods by me.
If you would like a copy let me know and I will send you a copy.

alfloyd


Life is Very Good

[garandsrus]

John Boy,

I have attached a spreadsheet that has the calculation for BHN while allowing you to make any alloy. This was published a year or two ago on this site. I originally created it and another member added the calculations for BHN and minimum obturation pressure.

John

[John Boy]

alfloyd ... what a fool I am! :groner:
I use Dressler's calculator and never in a 100 hundred years did I think about just doing the simple 1:X input for Sn to Pb by lb input! I thank you kindly for your offer, reminding me and apologize to all for my early dementia!

BTW, Jess revised the program again - effective Nov 2009 ... http://www.castbulletassoc.org/downloads.shtml

[John Boy]

John, thanks for your spreadsheet calculator also. Downloaded it and will makes some calculations

[James.358]

Hi there,

I use the alloy calculator Jess started but have made some changes. See Attached:

Cheers,
James

[medicms2001]

just want to say thanks for the calculators. Sure has made alloy making much easier. Much appreciated

[Guns N Glory]

Ok, I couldnt make sense out of any of the calculators, I cant do math, and I have no idea how to use a spreadsheet.

What I do have, is 220 pounds of alloy at Brinell 15, and I need it to be around Brinell 10. If someone could help me figure out how much lead I need to soften this batch It would be really great. Otherwise, I'm going to have to throw away this batch of alloy, and buy a few hundred dollars in pure lead to replace it.

[Grmps]

Mix 15 bhn 50/50 with pure 5bhn to get what you want

[dondiego]

Ok, I couldnt make sense out of any of the calculators, I cant do math, and I have no idea how to use a spreadsheet.

What I do have, is 220 pounds of alloy at Brinell 15, and I need it to be around Brinell 10. If someone could help me figure out how much lead I need to soften this batch It would be really great. Otherwise, I'm going to have to throw away this batch of alloy, and buy a few hundred dollars in pure lead to replace it.

What is wrong with 15 BNH metal? If you throw any away, be sure to tell us where you threw it please!