Lee hardness tester and alloy hardness

[trooperdan]

I have a new Lee hardness tester and I'm not sure of the answers I'm getting with it. I don't have any "known hardness" alloy to use as a baseline.

I tested ingots, not bullets; on an ingot of dental x-ray lead foil, I read about an 8.2. An ingot from a source that described it as "nearly linotype" I read about a 12.

Lee's instructions for testing a boolit say to file a small flat on the side of the boolit; in the case of water-droped slugs is the hardning just a surface hardning of does it go deeper?

And lastly, what hardness should I be looking for for boolits destined for a studly .41 mag load?

Thanks guys!

[Buckshot]

..............Dan, go to a chemistry place and buy yourself a 1 pound bottle of pure lead. It's 4.6 bhn but just take it as 5. Close enough. You can baseline from there. Pure lead is pure lead. Anything else is someone's idea.

.............Buckshot

[drinks]

Dan;
Send me your mailing address in a pm and I shall send you a couple of .44rfn cast of new linotype from Midway USA that you can use for a test standard and a few bullets of materials I have tested and my results on them, as suspect as the results may be.
Don

[Blacktail 8541]

I've been thinking of trying a lee hardness tester. Please give an update as soon as possible. Your impressions as to ease of use and accuracy would be appreciated also.

[trooperdan]

Drinks, I recieved your samples yesterday and checked them using the Lee tester. Below are the results:

1-43 WW-Pb mix, I measured about 12.5 to your measured 10

Aged WW                      "           14              "         14

WC-WW                        "            27              "         27

new lino                     "           20

The lee tester would greatly benefit from some type of mount as opposed to being hand-held. Objects are reversed in the view of the microscope so it takes a while to learn to move left when you want the scale in the view to move right. It is tough to line up the scale and keep things still while you decied how many graduations while the indent is. Still, all in all, I was pleased that my readings were so close to what you had measured. I didn't look at your measurement before I made mine to avoid being subconciously being influenced.

Drinks, thanks for the samples! I'll try to either return to favor or at least, pass it on to another shooter.

[Blacktail 8541]

Happy to see such simaliar results Will probably have to try one out.

[drinks]

TD;
Thanks for the report.
Just pass it on, I do quite a bit of that.
You think you have problems holding still, I am past 65!
If the site will let me, I shall post my solutions.
The first was a recycle of a junk kid's microscope I had in my jun, uh recycled treasures box.
The second is a fast home made tool holder, I made the rack and pinion from a piece of 3/8" all thread, split and filed to a uniform thickness and the drive gear and shaft from a blown Radio shack DC motor.
A table saw is nice, but it can be made with just hand tools.
Don

[montana_charlie]

I posted this on a different forum a week or so ago.
Seeing this discussion, and a request for 'more information' regarding impressions and ease of use I decided to go grab a 'copy' and drop it here.

I was given a Lee Lead Hardness Tester for Christmas.
It uses the same basic method as the 'drill-press-and-bathroom-scale' (and more scientific testers) in that you indent the alloy with a hardened ball of a given diameter...at a given pressure...and measure the diameter of the 'dimple' that is created.

The part which holds the indenter ball screws into your loading press and you use the ram to bring the sample up against it.

The Lee tester uses a ball of 5/32" diameter (I think), and includes a pocket microscope with a scale etched across the field of view. You read the width of the 'dimple' on the visible scale, and check that size against a table to find the equivalent Brinell Hardness Number.

The table which accompanies the Lee unit leaves something to be desired when testing very soft materials because the data doesn't go below BHN 8.

Since I am trying to test lead that I believe to be pretty pure, the lack of data for the softer ranges has been rather disappointing to me.
I sent an email to Lee today to see if they can provide information to amend my table to include BNH equivalents for those 'bigger dimples'.

My (supposedly pure) lead gets dimples which run the full width of the .100" scale. I tested some certified Tin today, and the dimples were .082"

Extrapolating the table downward, .082" seems to be about right for Tin with a BNH of 7, so I am guessing that .100" is pretty close for pure lead.

I am explaining all of this in such detail (Black~Feather) because you are contemplating the purchase of a hardness tester, and because I have seen a thread or two where someone asked about the Lee unit...and nobody ever answered.

I believe the Lee tester can provide results that are as accurate as those from the Saeco unit, but the data table needs to be expanded to include softer alloys.
With that 'improvement' I feel it would be equal to the Saeco tester...as well as being much lower in cost.

Now, a couple of weeks later, I am not as happy as I originally thought I was.
I made up a batch of 30-1 alloy which would have an expected BNH of 9...and that IS within the limits of the data table.
Unfortunately, my 'dimples' are bigger than the chart says they should be.

Now, maybe I'm reading it wrong. It's true that it's tough to get the microscope targeted correctly. If that's the problem, I can't speak very highly of the Lee unit when it comes to 'ease of use'.

I have written to Lee. If they answer, I'll pass along anything which might be helpful.
CM

[drinks]

Charlie;
Several of us on another forum have been comparing tests, using the LBT tester, the Saeco, the Cabine Tree and the Lee.
All of us are getting very close readings, the variables with the Lee have pretty well been narrowed down to human error, not timing correctly, pressing too hard or lightly and having a poor support or lighting.
I am going to try posting a table that takes the Lee readings down to .100", BHN 5, that is pure lead.
One thing we have been noticing, mixing alloys we have been told will be so hard may get results we are not expecting, time of ageing is important, some waterdropped went from 12 to 26 in 24 hours, some air cooled actually dropped in a few days.
I would say, believe the tester, if you have eliminated the human error factor.

[montana_charlie]

I am going to try posting a table that takes the Lee readings down to .100", BHN 5, that is pure lead.
One thing we have been noticing, mixing alloys we have been told will be so hard may get results we are not expecting, time of ageing is important, some waterdropped went from 12 to 26 in 24 hours, some air cooled actually dropped in a few days.
I would say, believe the tester, if you have eliminated the human error factor.

I assume the included table is the one for the Lee that you mentioned. Thanks.
I asked Lee to do that same thing, and they said it couldn't be done.
Seems a larger ball would have to be used...???
If you'd like to see exactly how they worded that, I still have the email.

As for the hardness of home-mixed alloys...
I have some lead which I believe to be pure.
I mixed .666 lbs. of certified tin into 20 pounds of the lead for a 30 to 1 mix.
If the lead is not actually pure, the mix should be harder than expected 'cause it can't go the other way...right?

My Lee tester (if human error is not to blame) says the alloy is SOFTER than BHN 9.
I read about .080 on the microscope scale. My alloy is always air-cooled and the test was performed the day after the stuff was mixed...and about an hour after the test bullets were cast.

Thanks for your intrest and encouragement to believe the tester. I will mess with it a bit more before deciding whether to give it back to Lee.
CM

EDIT ADDED...
I had sent an email to Lee requesting the 'loan' of another testing kit to compare side-by-side with mine.
This would verify that mine is good...or bad...and I could then decide whether the Lee unit is worth having.
In my explanation of 'why' I hoped for their agreement on this, I mentioned that the possibility exists that my tester is not correctly calibrated...or the spring is bad in some way.

Their response came in today, and they are not willing to send me a 'loaner'. But, they told me how to check calibration on mine.

They said to apply a 60 pound load to the indenter ball.
That should raise the shaft up to flush with the aluminum cap.

Now you know, too...in case you were wondering.
CM

[marlin55]

I made my own Hardness Tester, which is easier to read and I believe more accurate. The basic idea is to press a round ball into a piece of lead and get a read-out in hardness. Here is what you need: A round steel ball 0.5 in.dia. A drill press. 3) a bathroom scale. I have worked out the figures of the BRINELL SCALE. My WW lead bullets for Pistol and Rifle arew 13.5 BHN. If anyone is interrested let me know and I will go into details. marlin

[montana_charlie]

If anyone is interrested let me know and I will go into details. marlin

I've heard about a method which uses a drill press and a bathroom scale, marlin55. Go ahead and post those details cuz they might come in handy for me...or someone else.
Meanwhile, I'll look for somebody to help me get my drill press into the bathroom...
CM

[marlin55]

O. K. Here it is. Items to get: 1 pair of calipers. Imported ones for $ 10.00-15.00 are ok.
You are not after 0.0005 in. measurements. One steel ball 0.5 in. dia. One bathroom scale.
Get a Pipe cap and take the threads out on a lathe maybe. I welded a rod to it as a handle. Nothing fancy. All this is for to pour some lead into it for a sample to be measured
Fasten a board to the drill table and set the bathroom scale on it. Chuck a bolt into the jaw.Top of the Bolt faces downward. Now I took a dowel about 1.5in. diameter drilled a hole into it and epoxied the steel ball into it. The steel ball is being pushed down onto the sample of lead. Look on your bathroom scale and pull the chuck down until you get 200 lbs of pressure. Hold it for about 30 sec. and take it out. Take your caliper ang get a reading. called Brinell hardness test. I made up a chart that I will print in a few days. The advantage is that you read larger indentations. Pure lead is about 0.090 in. Let me know if you need any explanations. Marlin

[marlin55]

Correction: Pure Lead is 0.190 in. indentation. Sorry about that marlin

[David R]

I get .190 with a 5/16" ball and 150 lbs using Buckshot's Proven Lifetime Lasting hardness tester.

David

[marlin55]

Well, What can I say. If this works for you stick with it. I still stick with BRINELL formula that gives me 0.180- to .190 for pure lead. and Lyman Alloy # 2 at 15 BHT
at 0.110 indentation. If anyone uses different formulas go ahead. I do not intend to defend the Brinell formula. Good Luck to you.

[CollinLeon]

Yeah, I know this thread has not been active for quite awhile, but I read it while searching for info on the Lee Harness Tester and I figured I had a relevant comment...

With respect to the suggestion to create your own tester with a drill press, a 1/2" ball, and a bathroom scale, one other option might be to take a 1/2" drill bit, use a lathe to round the back end to a hemisphere, and then put it in your drill press in reverse. Of course, this assumes that you have a lathe that is as precise in measurements as the steel balls are that you can buy...

I read elsewhere on the web where someone took the bullets, put them in his 2400 dpi scanner, scanned the dimples, and then use his graphics editing software (GIMP) for measuring the distance across the dimple instead of using the Lee pocket microscope. I think he said that it would even work acceptably even with scanners down to 600 dpi. Probably a good solution for those of us with old eyes.

For the ultimate ball to use in this, I discovered some stainless steel and some tungsten carbide balls for sale on the web...

[CollinLeon]

I get .190 with a 5/16" ball and 150 lbs using Buckshot's Proven Lifetime Lasting hardness tester.

David

Using the formula, that calculates out to be a BHN of 3.336336167.

H = 2 * P / (pi * D * (D - sqrt(D^2 - d^2)))

Where:
H = Binell Hardness Number
P = Force applied (in kgf)
D = Ball diameter (in mm)
d = Indentation diameter (in mm)

Assuming conversion factors of:
2.204622 lbf per kgf
25.4 mm per inch

Now, if you want to create a table of indentation diameters given a specified ball diameter, force applied, and Binell hardness number, you can use the following equation:

d = sqrt( D^2 - ( ( 2 * P / ( pi * D * H ) ) - D ) ^2 )

This equation is pretty useful for creating a chart (in a spreadsheet) like the Lee chart for your own homemade hardness tester.

[montana_charlie]

Since you brought this thread out of the cemetary, I can add something to it, too.
My complaining about the dimple size being too large has been explained over the years.

I was trying to get the Lee tool to give readings that agreed with the Brinell numbers found in the standard tables that are everywhere.
I learned those tables have been wrong for decades, but nobody seems to know or care.

The 30-1 alloy that I couldn't get to read at BHN 9 has never been that hard.
A proper reading for that alloy is BHN 6.6.

So, what the Lee tool tells you is the truth. It's the data that you compare it with that is wrong.

CM

[CollinLeon]

So, what the Lee tool tells you is the truth. It's the data that you compare it with that is wrong.

Which just goes to show you that you should use the equations and create your own table of values.

It's simple high school algebra to take the original equation and solve for 'd' (the indentation diameter). All you need to do after that is plug it into successive rows of a spreadsheet. Or you can use the original equation to calculate the BHN each time instead of creating a table of values. Personally, I think that it is easier to look up the value from a table.