Patents Assigned to The United States Mint
  • Patent number: 10472703
    Abstract: The metal alloy is a possible replacement for/alternative to cupronickel cladding material used on currently-circulating clad coins. In the preferred embodiment, the (steel) metal alloy cladding material comprises 73-77% iron, 22-26% nickel, 0.2-0.5% carbon, and 1-5% manganese. The cladding material has an International Annealed Copper Standard (IACS) conductivity of less than 2%, a permeability of approximately 1.0-1.1, and a hardness value of 50-70 HRC 15 T (Rockwell Hardness). In alternative embodiments, the steel alloy comprises a monolithic coin or a core that may be plated with other metals.
    Type: Grant
    Filed: April 2, 2018
    Date of Patent: November 12, 2019
    Assignee: The United States Mint
    Inventors: Tsineng T. Ying, Richard R. Robidoux, Uvon Tolbert