[SEL] How do I tell Babbitt from Lead?

[John Culp]

That "ring test" doesn't work, BTW, if the lead's been heat treated by 
water quenching just below the melting point. I'm a bullet caster and 
do a lot of that. Lead alloys containing antimony, arsenic, or a bunch 
of other metals that will go into solid solution in the lead at 
elevated temperature will harden WAY up that way. The alloying 
elemnt(s) won't stay in solid solution at room temperature and 
crystallize out in a much finer grained structure than with slow 
cooling, pinning the atomic planes of lead together in many places so 
they can't slip by one another easily. Plain lead-antimony wheelweights 
will make harder bullets than those cast of air-cooled linotype if 
properly quenched and aged for a couple of weeks to reach maximum 
hardness. Quenched bullets also jingle like little bells instead of 
giving a dull rattle when shaken together.

John Culp
Bristol, Tennessee, USA