Hello!
I'm looking for a way to test my lead alloy hardness.
Anyone tried to design a good and simple lead hardness tester, around here?
PP.
Hello!
I'm looking for a way to test my lead alloy hardness.
Anyone tried to design a good and simple lead hardness tester, around here?
PP.
"Toutes des salopes sauf ma maman!"
I just ran across one in the Art of Bullet Casting Collection DVD.
You need a 10/mm (7/16) ball bearing, a drill press, and a bathroom scales.
You push down on the ball bearing into the lead sample using the quill of the drill press, until you reach 200 lbs. Hold it there for a couple of seconds, then measure the indent. There was a graph to compare the sample dent to read the hardness.
I also have an LBT tester, and they pretty much give the same readings.
I can grab the chart and post it if anybody's interested.
R.M.
Try this site.
http://www.castingstuff.com/
Easy Ed
.............By measuring the width of an impression to determine hardness you have to calibrate it. The diameter of the ball bearing isn't really important so long as it will not be pressed into pure or really soft lead so far as to be un-useable. R.M. mentioned 7/16 and that's a common size. A bit bigger or smaller doesn't matter. Nor does the pressure applied so long as it will make a definate impression in very hard lead. Again the quoted 200 #'s is common but 150 lbs is sufficient.
To calibrate an inpression tester you need the purest lead possible. You can order lab grade pure lead from a chemical or lab supply outlet. It'll normally come as a powder or granulated type. THe farther away from pure lead you get for your calibration efforts, the more skewed your other results will be.
Cast up the pure lead into an ingot of 1/2" thickness minimum, then make several impressions staying away from the edge. Your impression diameter then becomes your baseline constant you can use with the Lyman formula to determine hardness. Lets say your impression in pure lead is .198" in diameter.
The formula is:
.198" divided by the impression in the unknown sample, say it's 'X'.
Then you multiply the result X by itself, or X times X which equals Z.
Now you miltiply Z by the number 5 (a constant) which gives you the answer as a BHN number.
So: .198"/.150" = 1.32 then 1.32 x 1.32 = 1.7424, and 1.7424 x 5 = 8.712 BHN
Personally I'd round that 8.712 to either 8.7 or simply 9 bhn, as that would certainly be close enough.
..............Buckshot
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I have the world famous Buckshot hardness tester. I have had good luck with it. I am going to try an experment. After reading Richard Lee's book, he sez for best results the ball should penatrate from 1/4 to 1/2 of the diamater. I am going to put a smaller ball on mine to see if he is correct. I seem to get results that are harder than they should be. Could be the nut behind the wheel.
I have checked the calibration of the spring and its right on at 150 lbs. It also came with a lab grade pure lead sample and this neat little ingot maker (mold). Best tester for the money. I don't think they are available any more, so mine is worth more yet.
Thanks Buckshot
David
I made up a version of my own.I wanted somthing that I could carry with me for testing scrap and somthing I could make for other guys on my team.So simple was the word. I used a piece of CRS bar that would just slide through a piece of 1.5" pvc. Centerdrilled and brazed on a 7/16 ball. To use a 2 foot piece of 1.5" pvc is held over the sample.Drop the bar through.Measure the dent.I gave everyone a ingot of pure PB,WW and monotype. Oh the barstock weight is 2lb.
Cheep and works well enough for what it cost.
If shooting,fixing,making and thunking were easy.Everyone would be doing it.
There are four types of homicide: felonious, accidental,
justifiable, and praiseworthy.
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Jim
I also have one of the RARE and VALUABLE Buckshot Model II's set up on a RockChucker. Works like a dream. As David indicated Buckshot not only provided a pure lead test disc but also a nifty little mould for making discs out of your alloy to be tested !
GREAT SETUP !
Jerry
S&W .38/44 Outdoorsman Accumulator
Buckshot
The reason I used the figures that I did is because that's what the article said to use, plus, the supplied graph is meant for those figures. I agree with you totaly that you could plug in different sizes, but the graph wouldn't jive.
I've use4d your methood before, and I believe it to work, but you have to measure both samples and do the dreaded math
I just find my method somewhat easier, that's why I use it. I used your's before I found this one. For some reason, I don't have a lot of faith with the LBT tester. I have no idea why when it's the easiest one to use.
What it all boils down to is as long as we come up with about the same BHN, and are happy with how we got there.
".............R.M., What it all boils down to is as long as we come up with about the same BHN, and are happy with how we got there."
You're exactly right. You could do as Shooter 575 suggests and drop a weight through a pipe, or any other means to make an impression so long as it was consistant, and you had a pure lead comparison.
...............Buckshot
Father Grand Caster watches over you my brother. Go now and pour yourself a hot one. May the Sacred Silver Stream be with you always
Proud former Shooters.Com Cast Bullet alumnus and plank owner.
"The Republic can survive a Barack Obama, who is, after all, merely a fool. It is less likely to survive a multitude of fools such as those who made him their president."
Shrink the State End the Fed Balance the budget Make a profit Leave an inheritance
I haven't tryed it yet but this is a nice calculator and explanation.
http://www.gordonengland.co.uk/hardness/brinell.htm
Hope it helps.
Stephen
I now use the lee tester in one of them old cheesy lee hand presses...could not be happier...even found an extended chart online for what the lee chart did not cover...for the money it is hard to beat...just make sure you have plenty of light..I taped a 1 cell AAA minilight to the "MICROSCOPE" ...works just perfectly...find the measurement look it up in the chart...tahdah..
No math involved --- great for numerically challenged folks such as myself..
Show some pictures people !
I want to make one !
Here's one I designed and built a while back. Sent one to Dan, at Mnt. Molds to try out.
http://www.mountainmolds.com/phpBB2/viewtopic.php?t=162
Exellent ! Thankyou for the pictures.
Looks easy enough to make.
3.2.1 A CHEAP WAY TO TEST LEAD ALLOY HARDNESS
James Carter
I was reading a book from the late 50's at a friend's home that was put out by the NRA on how to test lead hardness on the cheap. I gave it a whirl and it works great so I thought I would share for those of you who are cheap like I am.
You need about 2 pounds or so of pure lead, your test lead and a steel ball bearing and a vise and a set of calipers/micrometer and that is it.
To get the pure lead you can find it in a metal supply shop but it runs about 3-4 bucks a pound or you can save the stick on weights when you find them in your bucket of wheel weights. I bought a couple of pounds to see what the difference was between it and the stick on version and the bhn number is about 5.2 or 5.3 instead of the 5 for pure lead, so close enough.
Drop by a bearing shop and pick up a 1" steel ball bearing and that costs about 2 bucks or so.
Melt the pure lead(stickon weights)in a muffin tin and your test lead in the one muffin slot next to it. I waited a day to test because I am anal that way.
Pad the vise with aluminum or steel on the jaws so that the lead doesn't dig into the teeth of the jaws. Hold up the lead in one jaw and the test lead on the other jaw and slowly squeeze the two together with the ball bearing in the middle. Just squeeze till there is a good dent on both surfaces of the lead or about 1/5 or the way in on both sides of the ball bearing.
Here is the formula BHN= 5 X (lead dia./test dia.)^2
With the calipers measure the diameter of the indent in each of the leads and plug in the values.
I had some WW and an unknown lead from a Radiator shop that I wanted to test and here are the results.
Diameter in Lead=0.479
Diameter in WW=0.325
So 5 x (0.479/0.325)^2 and that gives 10.8 BHN where it should be for air cooled Wheel Weights.
I had my friend test the WW on his Lee Hardness tester and he came up with 11so close enough.
Unknown lead from radiator shop
Dia. in Lead=0.520
Dia. in Unknown=0.279
So 5 x (0.520/0.279)^2 which gives us 17.4 BHN
I knew it was harder just with the old thumb nail test but I had no idea it was that hard. Again on the Lee it came back as 17 BHN
So this is a great cheap way to test lots of lead, it won't work so good on single bullets like the expensive models but at least you know what the raw materials BHN number is approximately.
Thanks, Joe.
I have seen that procedure before (can't remember where), but I needed the numbers - to use while waiting for Lee to send me a replacement hardness tester.
My original Lee would give me believable readings one day, and crazy ones the next. I tested the spring using the best setup I could manage, and it seemed to be right on at the required 60 pounds.
So, I started wondering about the microscope.
I thought I knew which way to point the cutout on the bottom to have the scale appear horizontal, but that seemed to change.
Then there were days when my old eye would have trouble focusing clearly.
Finally, I noticed that I could hear a faint rattle when I shook the microscope.
I don't know how many lenses are in the little thing, but I think one of them (or it) was moving around.
I just hate things which can't be disassembled and 'fixed'.
CM
Last edited by montana_charlie; 11-01-2006 at 03:55 PM.
Retired...TWICE. Now just raisin' cows and livin' on borrowed time.
A question about this...........If you can set a figure for the 'Pure Lead' indent then is it OK to just test the unknown material and use the lead figure as a constant.
If this IS the case, can you place an ingot of 'unknown on either side of the ballbearing and measure both indents or will the calc only work for an ingot on one side?
I know I am 3 years late here but lets just say I am a late developer
A DAY WITHOUT WINE IS A DAY WITHOUT SUNSHINE
Duncan
All of these test methods have their merits, but for utmost speed, simplicity and low cost, nothing beats the Pencil Hardness Test; Just scratch the lead with an art pencil. they commonly run from 6B to 12 H in hardness, but you won't need anything past 2H. Just sharpen the pencil tip to a wadcutter, and try to scratch the lead with it. If the lead digs in, it's harder than the lead. Lead hardness is equal to the hardest pencil that will not dig in. This is written up in more detals elsewhere here. If you really want the full details, check out the American Standard Test Methods in your local library.
Regards,
Molly
"The remedy for evil men is not the abrogation of the rights of law abiding citizens. The remedy for evil men is the gallows." Thomas Jefferson
I just finished 'testing' a number of wheel weight ingots using the ball bearing method and the pencil method.
In a total of 41 ingots tested there were the following results:
5-6 BHN x 2
6-7 BHN x 22
7-8 BHN x 12
8-9 BHN x 3
9-10 BHN x 2
When checked with pencils they all came out as 'H'
These wheel weights were from 3 different garages.
This would appear to show that the BHN test is more accurate but I would like to know if the variance found is large enough to influence the final castings.
It is important to say here that I have not cast rifle bullets before and so have not developed any technique yet.
I am casting for use in my Enfield No:4 using a Lee .309 160gr mold which I had to get from the UK because they were not available here in France
As casting materials here are like rocking horse s**t I intend to try hardening the bullets in an oven to increase their hardness. I can't find any sources of cheap material here, garages included!
A DAY WITHOUT WINE IS A DAY WITHOUT SUNSHINE
Duncan
I suspect that your pencil tip wasn't sharp. I've never had that problem. for me, pure lead tests about 6B, linotype tests about H. Maybe you need to read the full descrption in the ASTM books, which state that the deviation between two people and two pencil sets should not exceed one pencil if the test is conducted correctly...
Regards,
Molly
"The remedy for evil men is not the abrogation of the rights of law abiding citizens. The remedy for evil men is the gallows." Thomas Jefferson
BP | Bronze Point | IMR | Improved Military Rifle | PTD | Pointed |
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BT | Boat Tail | PL | Power-Lokt | SP | Soft Point |
C | Compressed Charge | PR | Primer | SPCL | Soft Point "Core-Lokt" |
HP | Hollow Point | PSPCL | Pointed Soft Point "Core Lokt" | C.O.L. | Cartridge Overall Length |
PSP | Pointed Soft Point | Spz | Spitzer Point | SBT | Spitzer Boat Tail |
LRN | Lead Round Nose | LWC | Lead Wad Cutter | LSWC | Lead Semi Wad Cutter |
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