What did I get ?

[legend 550]

What have I got here? I picked up some lead yesterday from a local scrapper mostly battery cable ends, wheel weights and lead pipe. 300# unsorted dirty lead at 38 cents/pound.
When I got home I found 20# of bars like this . I think they were made by National Lead they are 1/2" wide 1/4" thick 12 to14" long they say 2-5/8% on them.
pencil hardness test H skids 2H digs 20 BHN ?

54314

[Bullshop]

Looks like bar solder.

[I'll Make Mine]

That percentage of 2 5/8% is in the range common for tin-antimony lead free solders -- if that's the case, the bar should be significantly lighter than a lead bar the same size (tin is just over half the density of lead, and the antimony won't affect that much at that percentage).

[legend 550]

Guess I'll need to do some testing. I couldn't figure out what the 2- 5/8% was. Thanks.

[williamwaco]

If that stuff is 97% tin it is worth a small fortune.

[legend 550]

Well using my Lee .456 220gr mold for my Ruger OA I cast one from the mystery bar. My pure lead drop at 221 gr and the mystery bar dropped at 210 gr. I suspect the bars are a 60-40 solder? with 2-5/8 antimony. Anybody know how to calculate an alloy based on difference in weight for a given volume

54563

[a.squibload]

Ask Bumpo, bet he'll know.

[I'll Make Mine]

Anybody know how to calculate an alloy based on difference in weight for a given volume

As we used to say in high school and college math classes, "too many variables and not enough known values." For any given density within, say, 30% of pure lead there's a broad continuum of possible alloys -- tin, antimony, arsenic, zinc (up to 2%, at least in pure lead), bismuth, and a bunch of somewhat less common metals can all be alloyed to produce a metal with, in this case, about 91% of lead density.

For whatever it's worth, if the stuff is as much as 40% tin, it'll be lighter than what you have, but it'd have to be around 20% tin (discounting other components) or it'd be too heavy.