Testing for lead hardness

[Hondo Lane]

I have been casting lead bullets for 25+ years and have never had or used a lead hardness tester. Mostly because they were unobtainable. Now with the computer age and places like E-Bay (love it or hate it) A person can obtain any thing. So my question to you fellow casters is..."What do you use" and "What is the best gizmo out there". I am a collector of lead from various sources and can't seem to keep track of my lead-tin ratios so I think it is time to invest in a tester. Your thoughts Please...

[lwknight]

I can't remember where I got this write up but I'll plagerize it anyway.

L=Lead
X=Sample
(L^ / X^) * 5
Lead Hardness Test
Here is a simple way to test the Bhn number of unknown lead samples: all you need is a caliper, two bottle caps, a vise, a 5mm diameter (aprox. size) ball bearing, and a known pure sample of lead (Corbin can furnish pure lead of 99.995% Pb with trace silver).
1. Melt enough lead to fill one bottle cap with unknown sample, and the other with known pure lead. Make sure the surface is smooth and flat when the lead hardens and cools.
2. When the lead is cold, put the ball bearing between the two lead surfaces and squeeze this "sandwich" in the vise until the ball is driven partly into both surfaces (just enough to make a fair sized dent, but not past the middle of the ball).
3. Remove the sandwich and measure the two dent diameters. First measure the known pure lead dent and write down this number. Then measure the dent diameter in the unknown lead sample and write it down. Square both numbers (multiply times themselves). Then divide the resulting square of the unknown lead dent diameter into the square of the known pure lead dent diameter. This could be written as (L times L) divided by (X times X) where L is the pure Lead dent diameter, and X is the unknown lead dent diameter.
4. The answer should be a number of 1 or greater. If it is a fraction, or less than 1 in value, you have inverted the two dents and divided the wrong way. In that case, try again. When you get an answer that is 1 or greater, multiply it by 5. This is the actual Brinnell Hardness Number of the unknown sample.
The reason that you will always get a number of 1 or greater is that the ball will always go further into soft material (pure lead) than it will into hard material (any alloy of lead with tin, bismuth, antimony, etc.). Therefore, the diameter of the dent will always be smaller in the unknown sample, if it is harder than pure lead, or the same as the known pure sample, if it is also pure lead. When you divide a smaller number into a larger one, you always get something greater than one for an answer. Brinnell numbers are all greater than one. You must multiply the answer by 5 because this is the adjusting constant for pure lead, which is Bhn 5 hardness.
This method is as accurate as your sample purity and your ability to read the diameter of the dent. A smooth surface is necessary so you can get a clean diameter to measure. A rough surface will throw off the answer because you may not get a true diameter to measure, if one side of the lead surface is higher or wavy. But in general, this is as accurate a method as any that uses tools which cost less than $500. A reading with an accuracy of only Bhn plus or minus 0.5 will be more than sufficient for purposes of swaging. When the Bhn number actually increases from 5 to 10, or doubles, the pressure goes up by a factor of four, or the square of the increase in hardness. A number of 5-6 Bhn is close enough to be called pure for swaging purposes. A number of 10-12 is close enough to be considered about "medium" hardness or suitable for -S dies. A number of 18-20 is hard enough to be considered strictly for the -H type hydraulic dies even if used in the CSP-2 hand press.

[RobS]

If a person doesn't want to build one then the Lee is the least expensive and seems to have good consistency once a person gets the hang of things. The only problem for many with the Lee is the little microscope as it is hard to steady it. There are some links though that shows how others have remedied this issue. Here are a few links:

http://castboolits.gunloads.com/showthread.php?t=85157&highlight=Lee+hardness+tester

http://castboolits.gunloads.com/showthread.php?t=73590&highlight=cheap+hardness+tester

http://castboolits.gunloads.com/showthread.php?t=69416&highlight=cheap+hardness+tester

http://castboolits.gunloads.com/showthread.php?t=59923&highlight=cheap+hardness+tester

[John Boy]

I am a collector of lead from various sources and can't seem to keep track of my lead-tin ratios so I think it is time to invest in a tester.

Here's a couple
http://www.leeprecision.com/cgi/catalog/browse.cgi?1276206184.2645=/html/catalog/bullmol1.html#LeadHardness

http://www.castingstuff.com/cabinetree_loading_products.htm

[Hondo Lane]

I have been looking at the "LEE" tester on Evil-Bay but haven't commited myself to purchase. I plan to start doing some more shooting with cast so it would probably pay. Bore leading is a pain. I want to add a .45 cal. auto pistol to my collection and they are ammo hungry. Even buying pre-cast slugs it probably wouldn't hurt to check what you are buying.

[melloairman]

I have a cabine tree tester and like it . I collect range lead and test all my ingots with it . Marvin

[fredj338]

I had a Saeco, like it fine. It's a bit pricey now & a little more diff to use than the CabinTree, but nicely made. I sold it & bought a CabinTree, mostly because I can do ingots w/ it. The LBT is also good, but has a short, I think 1" max, bullet length. The Lee, well, only if I was forced to.