Low cost Lead Hardness Tester

[Faret]

If you know the ratio of your press linkage can't you hook up a fish scale to the handle and measure the weight that way?

[Cloudpeak]

Greetings
Another form of the above mentioned form is to take two similar ingots. One of pure lead and the other of the unknown. It helps if the two ingots are flat sided. Place the steel ball (I use a 1/2") between the two ingots and smack forcefully with a 3# hammer. Both ingots are now impressed. The pure lead will have a larger diameter crater (softer material). Now it is just a matter of measuring both and doing the math. As some as soon as I can find the factor I will type it in... where did it go ?
But this system is reasonably accurate for hardness. It matches closly what my LBT hardness tester
will show and only costs time.
Found the info & thanks to JOHNBOY.
First measure the indents in BOTH ingots with a Dial caliper.
Square the measurements.
Divide the unknown ingot SQUARE result into the Pure Lead SQUARE result.
Multiply by 5 and you now know the Brinell hardness opf the unknown ingot.
Remember this does NOT tell you the lead composition. That can only be know by analysis of the ingot.

The math didn't seem to work for me. Perhaps I did the math wrong. Here are my results using your formula:

-----------------Step one------Step two--------Step three----- Step four
Wheel Weights---0.06330------0.00401---------6.03467---------30.17334
Stick on-----------0.06700------0.00449-------- 5.38656---------26.93278
Range Scrap-----0.07000-------0.00490--------4.93474---------24.67372
Pure Lead--------0.15550------- 0.02418--------1.00000----------5.00000

Step one: First measure the indents in BOTH ingots with a Dial caliper.
Step two: Square the measurements.
Step three: Divide the unknown ingot SQUARE result into the Pure Lead SQUARE result.
Step four: Multiply by 5 and you now know the Brinell hardness opf the unknown ingot.

I found it interesting that my stick-on's and range scrap were much harder than I expected. I expected stick-on's in particular to be much softer after reading posts on this forum. I also did the "drop on floor, listen to the sound" test and was able to sort the ingots just by sound to the same order that I found in testing.

[machinisttx]

Great idea!

Now could you invent a way to compare hardness, toughness, brittleness .....

Actually, no kidding. I want to be able to 'measure' different properties of an alloy like hardness at softest and max hardness plus impact hardness versus BHN.

Thing is, to get batch to batch repeatability without using pure base metals .... You know what I mean.

If you want to test toughness, check this link

[Gelandangan]

I tried Jbunny's method on post #9
I successfully measured a few different metal (of known hardness) by interpolation.

Instead of rectangular shape notching tip, I ground mine in a sort of elongated hexagonal that look like < >
So I can measure the tip of the notch easier.
I use a digital caliper to measure the width of the notch.

Starting measurements:
Pure Lead ingot (BHN 5) measured to be 3.02 mm wide
Lyman No 2 mixture ingot (previously measured BHN 15) measures 1.97 mm wide

So with the above result, I deduct that each notch width reduction of 0.1mm is corresponding to about 1 BHN increase in hardness.
How is that for a convenient coincidence?

Now, I get a piece of clip on WW, notched it and measure the notch to be 2.32mm (0.7mm less than lead)
thus the hardness of the WW is approximately 12 BHN - which is about right .
I also get an ingot of clip on WW that I made up a few weeks ago, it measures the same as the raw WW at BHN 12

Next I got a piece of 20 - 1 ingot I bought a while ago.
The tool made a notch of 2.53 mm which corresponding to about 10 BHN

Thus from the experiments conducted, I deduce that this tool actually works!
At least it works for materials between 5 and 15 BHN.

[TBuller]

Made this hardness tester with a 60lb gas strut from Amazon. A pair go for $15. I compared results with a pencil hardness test and they came out pretty close to one another. Seems to work best if left under pressure for a while. One of the other posts mentioned 30 seconds and that seemed to produce good results for me also. This one uses a 5/32 ball bearing also from Amazon.

[gzig5]

I've got a few extra air cylinders in the cabinet with 3/4 and 1" piston diameters. Should be pretty easy to fab up a fixture and figure out the pressure needed to give 60lbs on the rod end. I can compare to my LEE kit. I'm not too concerned with exact BHN, more how my different alloys compare and what the junk I bring home can be used for.

[remy3424]

Does no one use the drawing pencils? Doesn't get much easier and quicker.