This section is from the "Henley's Twentieth Century Formulas Recipes Processes" encyclopedia, by Norman W. Henley and others.
Copper, 1 part; zinc, 1 part; tin, 1/10 part; lead, 1/10 part. Very readily fusible and very dense.
Birmingham platina is an alloy of a pure white, almost silver-white color, remaining unaffected by tolerably long exposure to the atmosphere. Unfortunately this alloy is so brittle that it can rarely be shaped except by casting. It is used only in the manufacture of buttons. The alloy is poured into molds giving rather sharp impressions and allowing the design on the button (letters or coat of arms) to stand out prominently with careful stamping. The composition of this alloy, also known by the name of platinum lead, is as follows:
Copper............ 46.5 4
Zinc............... 53.5 16
Zinc, 80 parts; copper, 10 parts; iron, 10 parts.