Basic Rules for Hardening Lead taken from rotometals.com
For every 1% additional tin, Brinell hardness increases 0.29
For every 1% additional antimony, Brinell hardness increases 0.92
Sample equation:
Brinell = 5 Brinell Pure Lead + (0.29 * Tin percentage) + (0.92 * Antimony percentage)
If you increase the amount of tin by 10% and the amount of antimony 5%, the brinell hardness of your lead will be 12.5
Brinell hardness 12.5 = 5 + (0.29 * 10) + (0.92 * 5)
