Idaho Ron
58 Cal.
- Joined
- Mar 1, 2007
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I was asked to test some lead for Jethro224. But while we were on the conversation he had an experiment. I hope this is okay to repost this Jim since this is for science :idunno: .
The test was this. This was the note from him.
"Does lead work-harden if you flatten it with a hammer? Would that affect the temperature it melts at?
These questions were brought up at a rendezvous during a discussion about casting ball on a woodswalk when a buddy had to melt some lead over a fire and cast a ball in a certain time.
Someone told him to hammer a ball flat so it would melt faster. An oldtimer said that hammering a ball flat would harden it and it would melt slower.
Later that day, my buddy and I were discussing this and trying to figure out who was right."
Okay, I got 8 cast round balls from Jim and decided to not only give him the hardness of his lead but to try to figure out at least part of the test.
I filed two balls and tested them on both sides. The hardness was
#1- .045 - .045 this would be about 8 BHN
#2- .030 - .045 This would be between 7 and 8
CVA round balls are .018 or 4 BHN
TC maxi balls run .024 or 5 BHN
Before I hear from someone that says pure is 5 BHN!!! I understand. But my tester is capable of testing lead that is almost butter. The ability to test this way gives me the ability to see lead that is softer than the normal .020 to .030 that is normally 5 BHN.
On to the next test. I hit two balls with the "same" hit and measured them for thickness and hardness. Same lead as the test above.
#3- .060 hard and 0.464" thick. Hardness 9.2 BHN
#4- .062 hard and 0.446" thick. Hardness 9.5 BHN
WOW!! I have never done this test. So I decided to do another. This one I would use a larger hammer and flatten it a bit more.
#5- .059 Hard and 0.295" thick. hardness 9.2 BHN
#6- too flat to test :td:
It seems that work hardening might have a ceiling.
So I dug into every box I could find and I could not find any more factory round balls to smash test. So I decided to try a ingot.
Ingot test. This is an ingot that I alloyed for my 50 cal paper patched bullets.
#1- as cast .038 hard or 6 BHN
#1 smashed .053 hard or 9 BHN.
To test the ceiling I pounded it big time. I took it down about 1/2" and it actually went the other was
#1 smashed way hard and flatter .045 8 BHN
Well the question was will smashing them flatter make them harder? The answer is yes to a point, but. I am not a master of science so my thinking is the lead was smashed and it was made denser. The only way to actually harden lead is to alloy it.
The second question about thinner lead melting faster. I didn't test this but. I do have them marked and maybe in the future I can get some time to do this. But my thoughts.
Pure lead melts at 621.3 degrees or so.
Tin melts at 449. It is thought that pure with tin melts at 600 but that depends on the amount of tin. Tin is considered to only harden lead a little. What it mainly does is keep the melt homogenized and keeps the dross down to about 750 degrees. Again depending on the amount.
Antimony melts at 1167 degrees and it is what is used to strengthen and harden lead.
Other alloy is also used but I am not going any farther.
Again it is my opinion that the smashed lead is work hardened only but to a point. It is not truly hardened and by that I mean alloy added. So again does the thinner ball melt faster? I think it could. I doubt that it would take longer because the composition has not changed.
Thoughts? Thanks Jim for the lead to test with.
Ron
The test was this. This was the note from him.
"Does lead work-harden if you flatten it with a hammer? Would that affect the temperature it melts at?
These questions were brought up at a rendezvous during a discussion about casting ball on a woodswalk when a buddy had to melt some lead over a fire and cast a ball in a certain time.
Someone told him to hammer a ball flat so it would melt faster. An oldtimer said that hammering a ball flat would harden it and it would melt slower.
Later that day, my buddy and I were discussing this and trying to figure out who was right."
Okay, I got 8 cast round balls from Jim and decided to not only give him the hardness of his lead but to try to figure out at least part of the test.
I filed two balls and tested them on both sides. The hardness was
#1- .045 - .045 this would be about 8 BHN
#2- .030 - .045 This would be between 7 and 8
CVA round balls are .018 or 4 BHN
TC maxi balls run .024 or 5 BHN
Before I hear from someone that says pure is 5 BHN!!! I understand. But my tester is capable of testing lead that is almost butter. The ability to test this way gives me the ability to see lead that is softer than the normal .020 to .030 that is normally 5 BHN.
On to the next test. I hit two balls with the "same" hit and measured them for thickness and hardness. Same lead as the test above.
#3- .060 hard and 0.464" thick. Hardness 9.2 BHN
#4- .062 hard and 0.446" thick. Hardness 9.5 BHN
WOW!! I have never done this test. So I decided to do another. This one I would use a larger hammer and flatten it a bit more.
#5- .059 Hard and 0.295" thick. hardness 9.2 BHN
#6- too flat to test :td:
It seems that work hardening might have a ceiling.
So I dug into every box I could find and I could not find any more factory round balls to smash test. So I decided to try a ingot.
Ingot test. This is an ingot that I alloyed for my 50 cal paper patched bullets.
#1- as cast .038 hard or 6 BHN
#1 smashed .053 hard or 9 BHN.
To test the ceiling I pounded it big time. I took it down about 1/2" and it actually went the other was
#1 smashed way hard and flatter .045 8 BHN
Well the question was will smashing them flatter make them harder? The answer is yes to a point, but. I am not a master of science so my thinking is the lead was smashed and it was made denser. The only way to actually harden lead is to alloy it.
The second question about thinner lead melting faster. I didn't test this but. I do have them marked and maybe in the future I can get some time to do this. But my thoughts.
Pure lead melts at 621.3 degrees or so.
Tin melts at 449. It is thought that pure with tin melts at 600 but that depends on the amount of tin. Tin is considered to only harden lead a little. What it mainly does is keep the melt homogenized and keeps the dross down to about 750 degrees. Again depending on the amount.
Antimony melts at 1167 degrees and it is what is used to strengthen and harden lead.
Other alloy is also used but I am not going any farther.
Again it is my opinion that the smashed lead is work hardened only but to a point. It is not truly hardened and by that I mean alloy added. So again does the thinner ball melt faster? I think it could. I doubt that it would take longer because the composition has not changed.
Thoughts? Thanks Jim for the lead to test with.
Ron
