Cheap lead hardness test
Here's a copy of an email I have kept for about 10+ years 'cause the same issue keeps popping up regarding how to tell the hardness of mystery lead:
Testing lead hardness w/ artists pencils To lead scroungers everywhere, I think I got this info off this list (CAS-L) 1-2 years ago. I would like to thank whoever originally posted it and offer my apology for losing the original credits. You can go to an art supply store and get a set or select individual pencils whose core varies from [softest] 9B,>>>1B, HB, F, 1H, >>>9H[hardest]. Lead will run about 4B or 5B, depending on purity, and linotype will run about HB, or F. The hardest pencils will test aluminum alloys and are too hard for lead. About 6 to 8 pencils will cover the range needed for informal casting. To use, shave the wood away to expose the "lead" core without cutting into it with the knife exposing 1/8-1/4". Hold the pencil vertical and sand the end flat on fine (about) 400 grit sandpaper. Hold the pencil in a normal writing position, and try to push the lower edge into the lead surface. If the graphite core is harder than the alloy, it will cut into the metal or at least seriously scratch it. If the metal is as hard or harder than the graphite core, it will not be able to gouge. The hardness is ranked as the hardest graphite core that will NOT cut in. If your bullet is resistant to pencils from 6B through 2B, but B scratches it or peels up a small shaving, the hardness is 2B.This isn't as exact as a Brinnel tester but cost effective enough for me. You can reproduce your hardness but not necessarily the same cost, or castability but all I want to know is whether it is REAL HARD, sorta hard, somewhere in between, soft, and REAL SOFT. I bought 8 pencils: H, HB, B, 2B, 3B, 4B, 5B, & 6B. I found that my various ingots of lead were not sorted well once I pencil tested them. Wheel weights and MY BLEND of #2 alloy are about 2B and my soft cap&ball lead is 4B&5B. Be sure to use a fresh surface as some of the heavier grey corrosion will resist the pencil core but the underlying lead will scratch.
