montana_charlie
01-31-2008, 09:37 PM
I sure need the 'combined mind' to help with this!
I contacted an eBay seller about some lead he had for sale. As usual, I questioned him closely about the source of his metal, trying to decide (for myself) how 'pure' it might be. After a couple of back and forth messages, it became apparent he was using a Lee hardness tester, but was not able to get a solid BHN for this metal
So, I sent him one of those charts that extends the Lee information downward...to reach BHN 5.
He still could not find a number that matched the reading in his microscope...said reading being clear off the imprinted scale.
Obviously, this poor, benighted, lead salesman need my help, so I got a sample from him.
Now I am in the same boat he is in!
The dimple in this sample is bigger than the microscope scale, and you can bet I operated the tool correctly. Using a dial caliper, the dimple diameter measures .133".
I have tried extrapolating the Lee chart down to this size, but keep getting a BHN around 3. I could use the help of a math wizard to check that out.
Then, there is the fundamental question...
I know that BHN 5 is generally recognized as correct for 'pure' lead, but what is the number for (say) 'virgin lead'?
That is the only term I have ever heard of which might explain metal this soft.
CM
I contacted an eBay seller about some lead he had for sale. As usual, I questioned him closely about the source of his metal, trying to decide (for myself) how 'pure' it might be. After a couple of back and forth messages, it became apparent he was using a Lee hardness tester, but was not able to get a solid BHN for this metal
So, I sent him one of those charts that extends the Lee information downward...to reach BHN 5.
He still could not find a number that matched the reading in his microscope...said reading being clear off the imprinted scale.
Obviously, this poor, benighted, lead salesman need my help, so I got a sample from him.
Now I am in the same boat he is in!
The dimple in this sample is bigger than the microscope scale, and you can bet I operated the tool correctly. Using a dial caliper, the dimple diameter measures .133".
I have tried extrapolating the Lee chart down to this size, but keep getting a BHN around 3. I could use the help of a math wizard to check that out.
Then, there is the fundamental question...
I know that BHN 5 is generally recognized as correct for 'pure' lead, but what is the number for (say) 'virgin lead'?
That is the only term I have ever heard of which might explain metal this soft.
CM