November 24, 2021 1 min read
Philadelphia Mint uses different bronze alloys in medals
By Paul Gilkes , Coin World, Published: Nov 24, 2021, 8 AM
The U.S. Mint employs planchets in two different alloys to execute production of its bronze medals at the Philadelphia Mint.
The difference in the compositions accounts for the difference in hue for the various versions.
The bronze duplicates of congressional gold medals are produced in 3-inch and 1.5-inch diameter versions. The Presidential bronze medals are struck in 3-inch and 1.3125-inch versions.
The 3-inch bronze versions are struck on planchets made of an alloy of 90% copper and 10% zinc, which have a more golden hue, somewhat similar to that of the Native American and American Innovation dollar coins (which have outer layers of a manganese brass alloy that includes 77% copper).
Some, but not all, of the 1.3125-inch and 1.5-inch bronze medals are produced on planchets of 95% copper, 5% zinc, and they exhibit a much brighter, reddish copper hue.
The bronze medals are struck at the Philadelphia Mint but without a P Mint mark.
The Mint offers the two smaller diameter medals for $20 each and the 3-inch bronze versions for $160 each.
The U.S. Mint’s catalog for bronze medals includes 3-inch medals with Bicentennial and Centennial themes, Code Talker medals, Historical Event medals, Humanitarian and Cultural medals, Military medals, Presidential medals, and Treasury and Mint medals.
The diameter of the smaller medals varies among the topical themes.
The original article can be found at https://www.coinworld.com/news/us-coins/philadelphia-mint-uses-different-bronze-alloys-in-medals