Low cost Lead Hardness Tester

[tvincent]

Attached you will find a chart. Use a .156" steel ball bearing (I mounted mine on the tip of a steel cone) and apply 60 pounds pressure for about one minute. I use a hydraulic pressure gauge, but you can use a common bathroom scale on a drill press. Measure the diameter of the indentation, then use the chart to determine the hardness.

Good Luck, I thought I would share this with the group.

Thomas

[Duhawki]

I'm curious how you came to select 60 pounds and a 5/32 inch ball.
Regards,
Duhawki

[RobS]

I've done a similar thing and the idea of using a 5/32" ball bearing with 60 lbs was not my mine, but is what Lee uses in their setup so that is what prompted me. I never liked the Lee tester as it uses an internal spring to regulate the pressure and I felt that with time the spring could lead to inconsistent readings. So I built my own where the pressure would always be consistent. I still use the same chart lee uses but measure the indention with a good set of digital calipers and a cheap magnifying glass from walmart which is easier than looking through the lee micro mini scope thing. The cost of this one was about $2.00 to make as I already had the digital calipers, the magnifying glass, and some scrap metal laying around. Here are some pics of my version.

[RobS]

Attached is a PDF file of what I put together for a BHN Chart...........it is basically the LEE Chart modified.

[bohokii]

neat maybe you could use a clicker type torque wrench instead of barbells

[missionary5155]

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.

[zomby woof]

Here's my method. I have a .312" ball, arbor press, 22LB weight and 30 seconds.


http://www.hunt101.com/data/500/medium/100_2996.JPG
http://www.hunt101.com/data/500/medium/100_29981.JPG

[RobS]

This has turned out to be a cool thread; all innovative methods to travel down a common road. Does anybody else have a little show and tell in them???:-P

[jbunny]

this is little jonny in the back row waveing franticly. pick me pick me.
i mostly use the direct kiss aproach. a $6 heavy duty chinnese spring punch
a few minnuits of grinding and presto, a hardness tester. just make yourself
a comparison chart and ur away. the wide punch bullet is WW water quench.
the small punch is zinc bullet. the bar is babbit mostly tin i think.

jb the nutty mcgiver


http://i138.photobucket.com/albums/q273/MOUICH/hardnesstester.jpg

http://i138.photobucket.com/albums/q273/MOUICH/hardnesstester2.jpg

[edsmith]

jbunny,that is brilliant.

[missionary5155]

JBunny That is one SUPER idea !

[jbunny]

thanks guys. now for the rest of the story.
the round ball tester has been around for a long time. u need real strong
optics the read the crater width. i tried the standard center punch carter and same thing. i then setteled on .080 thou thick v blade that gave me the widest crater
between hard and soft for easy reading with calipers. some of u will says the metal
don't flow that fast. this is not rocket science. look at some of the coins in your
pocket. notice the high reilef. ever see vedio's of these coin stamping machines.
the coines come of these machines like bullets out of a machine gun.
thats my story and i'm sticking to it
jb

[madcaster]

Great thinking!:!:

[303Guy]

Great idea!

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

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 .... [smilie=1: You know what I mean.

[GL49]

I've steered away from hardness testers because they are generally a pain. Good idea, jb. If anyone starts selling these, you should get your share.

[chris in va]

ever see vedio's of these coin stamping machines.
the coines come of these machines like bullets out of a machine gun.


Coins are made with pressure measuring in the tons.

[jbunny]

yes; because the metal being used is a lot harder than lead and to get the metal to flow in nano seconds they need serious pressure.jb

[Jon]

I love the idea of the punch tester. I just need something to give me a ballpark of the hardness. I need a range of materials to make a chart to work with, and interpolate from.

Is there anything readily available, and cheap to test for pure tin?

I have 60/40 solder to test in the middle.

I have some wheel weight ingots, but I'm not sure of the usual ratio for WW. Anyone have that handy?

I think I may have some lead flashing, but 44cal black powder balls would be pretty close to pure lead, right?

I have a bunch of range scrap that I'd like to get some idea of the hardness. Hopefully I can use it for my BP 1858 Remington, but I don't want to buy a mold if it will be too hard.

Thanks.

[Ctkelly]

Coins are made with pressure measuring in the tons.


yes; because the metal being used is a lot harder than lead and to get the metal to flow in nano seconds they need serious pressure.jb

About 150 strokes a minute, 400 ton stamping force. The machines themselves arent that large. I'm used to operating 150 ton DACI can presses that run 155 strokes but with 11 and 14 lanes of cans coming out of them. Just the tooling die that goes into the presses weighs more than a US mint press all together.

[Duhawki]

A couple of Brinell comments: (1) The load to ball diameter squared ratio is a critical characteristic of the measurement system. Brinell hardness measured at 3000 Kg with a 10 mm ball is exactly the same as Brinell measured at 750 Kg with a 5 mm ball because the ratio is 30 for both. (2) The Brinell test is only valid over a relatively narrow range of impression diameters: about 25% to 60% of the ball diameter.

A 5/32 diameter ball at 60 Lbs load has a load to diameter squared ratio of about 1.7 (using mm and Kg units) while the standard Brinell (for lead) is 100 Kg and 10 mm for a ratio of 1. The rule of thumb for convertability is +/- 25% from the reference ratio. So, A calculated Brinell value from impression diameters made with a 5/32 ball and 60 pound load is problematic.

Also, the low end of the Brinell range measureable at 5/32 and 60 lbs is not as low as some conversion charts suggest.

Regards,
Duhawki

[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 ..... :mrgreen:

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 .... [smilie=1: You know what I mean.


If you want to test toughness, check this link (http://en.wikipedia.org/wiki/Charpy_impact_test)

[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.

277191277193

[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.