The pure copper core makes up half of the metal in the coin, with the two layers of manganese brass
each taking up one-fourth of the thickness.
The new coin, manganese brass
over a copper core, is not intended to replace the paper bill, 6 billion of which are printed each year.
The new alloy is a three-layer "clad" system of manganese brass
Based on results of the electrochemical polarization and salt fog tests, high manganese brass
(C99700) is the most corrosion-resistant alloy and high strength yellow brass (C86300) and aluminum bronze (C95400) are the least resistant to corrosion.