Does tumbling the lead balls cause surface hardening?

[Bo T]

Does tumbling the lead balls cause surface hardening?

Just curious.

 

[ZUG]

No -- lead does not "work harden".

 

[Wes/Tex]

You can temper lead harder or anneal it softer using heat and slow or fast cooling but tumbling would never create that kind of temperature unless your tumbler was jet powered! :wink: :haha:

 

[coloradoclyde]

You can temper lead harder or anneal it softer using heat and slow or fast cooling :wink: :haha:

Must be an alloy to harden...

 

[FishDFly]

You can temper lead harder or anneal it softer using heat and slow or fast cooling but tumbling would never create that kind of temperature unless your tumbler was jet powered! :wink: :haha:

How does the cooling rate of molten lead change the chemical makeup of it???

 

[LRB]

I am open for references to the contrary, but as far as I know, pure lead cannot be hardened.The right alloys can harden lead though. Antimony or tin, or both together with lead makes the so called hard chilled shot Not any kind of heat treating.

 

[hanshi]

No, and there's no need for concern.

 

[Idaho Ron]

You can temper lead harder or anneal it softer using heat and slow or fast cooling but tumbling would never create that kind of temperature unless your tumbler was jet powered! :wink: :haha:

I will agree that with pure lead it can not harden unless alloy is added.
Once alloy is added that mix can be hardened by quenching it in water. Or it can be heat treated in an oven. Age will also harden alloy, the more alloy in the mix the harder it will get with age, or quenching. I have seen bullets that run 6 to 7 BHN ( a small amount of alloy) turn into 8 by quenching. If you quench a 5 BHN bullet it will not change to any extent.

 

[Onojutta]

Does tumbling the lead balls cause surface hardening?

Just curious.

Would it matter if it did?

 

[coloradoclyde]

How does the cooling rate of molten lead change the chemical makeup of it???

Pure lead, it doesn't
But a lead alloy, it does.

The temperature at which something cools affects the grain structure......

 

[Bo T]

It could have. As noted for revolvers, a harder ball increases the force required to seat it and could result in premature wear on the loading lever pivot. For single shots a harder ball equates to more force needed to seat the ball. I have an 1851 that I will return too after getting situated with flintlocks. But, given the information, it seems that all is good.

 

[Wes/Tex]

You can temper lead harder or anneal it softer using heat and slow or fast cooling but tumbling would never create that kind of temperature unless your tumbler was jet powered! :wink: :haha:

How does the cooling rate of molten lead change the chemical makeup of it???

Doesn't change it chemically, but lead balls heated in an oven at about 400 degrees for half an hour and carefully poured into cold water will created a hardened surface...the centers will still be soft. Have played with it but rally found no great use for the end product outside of possible deeper penetration. Alloy mixed balls will soften slightly if heated the same way then allowed to cool by turning off heat and letting them cool with oven door cracked open.

 

[Wes/Tex]

You can temper lead harder or anneal it softer using heat and slow or fast cooling but tumbling would never create that kind of temperature unless your tumbler was jet powered! :wink: :haha:

I will agree that with pure lead it can not harden unless alloy is added.
Once alloy is added that mix can be hardened by quenching it in water. Or it can be heat treated in an oven. Age will also harden alloy, the more alloy in the mix the harder it will get with age, or quenching. I have seen bullets that run 6 to 7 BHN ( a small amount of alloy) turn into 8 by quenching. If you quench a 5 BHN bullet it will not change to any extent.

I'm only speaking of slightly hardening the balls surface with heat tempering...it will not make the entire ball a harder consistency like adding alloy.

 

[Billnpatti]

You can temper lead harder or anneal it softer using heat and slow or fast cooling but tumbling would never create that kind of temperature unless your tumbler was jet powered! :wink: :haha:

How does the cooling rate of molten lead change the chemical makeup of it???

Doesn't change it chemically, but lead balls heated in an oven at about 400 degrees for half an hour and carefully poured into cold water will created a hardened surface...the centers will still be soft. Have played with it but rally found no great use for the end product outside of possible deeper penetration. Alloy mixed balls will soften slightly if heated the same way then allowed to cool by turning off heat and letting them cool with oven door cracked open.

That is very interesting. :hmm: I was of the opinion that the hardness of lead was not effected by rapid cooling or quenching. I am not a metallurgist so it was just one of those opinions that we hear so much about being likened unto an anal sphincter. I have quenched newly cast balls in water, dropping them directly from the mold into a bucket of water. The only reason for my doing so was simply lack of space to drop them onto an old towel as is my usual way of doing. It was just an expedient. Having done so, I did not notice those balls being any harder than the ones that I allowed to cool on an old towel. But, I did no actual measurement of the relative hardness of them. I have a pretty reliable method of measuring relative hardness and one of these days, I am going to run an experiment, or series of experiments, to see for myself just how much hardness is effected by quenching hot lead. It may not be today or tomorrow but......someday. When I do, I will post my results for the amazement and amusement of our members. Yes, I may take flack but that's okay, I have taken flack before and survived so it doesn't scare me.

 

[Tinker2]

lead balls heated in an oven at about 400 degrees for half an hour and carefully poured into cold water will created a hardened surface...the centers will still be soft.

I have read that before.
I have also heard that they will lose that extra hardness over time.




William Alexander

 

[Idaho Ron]

You can temper lead harder or anneal it softer using heat and slow or fast cooling but tumbling would never create that kind of temperature unless your tumbler was jet powered! :wink: :haha:

I will agree that with pure lead it can not harden unless alloy is added.
Once alloy is added that mix can be hardened by quenching it in water. Or it can be heat treated in an oven. Age will also harden alloy, the more alloy in the mix the harder it will get with age, or quenching. I have seen bullets that run 6 to 7 BHN ( a small amount of alloy) turn into 8 by quenching. If you quench a 5 BHN bullet it will not change to any extent.

I'm only speaking of slightly hardening the balls surface with heat tempering...it will not make the entire ball a harder consistency like adding alloy.

Pure lead will not surface harden.

 

[Adui]

See; now I am wishing my Granddad was still alive. We lost him in 1990. He was a foundry-man, worked in a foundry with metals. He actually made some of grandma's cast iron pans.

I am betting if I asked him about this he's have an educated opinion...

 

[Billnpatti]

Back to the original question of whether or not tumbling lead balls will work harden them. I have not read anywhere that pure lead can be work hardened so my answer to his question would be no, tumbling lead balls will not harden them. Having said that, I must add that I am not a metallurgist, my training and experience has been in the medical and chemical fields. I was a Certified Industrial Hygienist. So, take my statement for what it worth.

 

[Many Klatch]

I know a shooter who tumbles the lead balls after he's done casting. He claims that it removes the sprue and makes the balls rounder. I don't know it it's true but he is awfully hard to beat.

 

[Claude Mathis]

Pure lead will not surface harden.

Correct.

Attempts to strengthen lead by reducing the grain size or by cold working (strain hardening) have proven unsuccessful. Lead-tin alloys, for example, may re-crystallize immediately and completely at room temperature. Lead-silver alloys respond in the same manner within two weeks.

Transformations that are induced in steel by heat treatment do not occur in lead alloys, and strengthening by ordering phenomena, such as in the formation of lattice superstructures, has no practical significance in typical lead alloys. In one study of possible binary lead alloys it was found that the following elements, in the order listed, provided successively greater amounts of solid-solution hardening: thallium, bismuth, tin, cadmium, antimony, lithium, arsenic, calcium, zinc, copper, and barium.

http://www.lasc.us/HeatTreat.htm