Abstract
Bluing on coins is a common phenomenon in proof coin manufacturing. Thousands of coin collectors use magnifying glasses, even microscopes, to observe coin bluing. If dissatisfied by the appearance of the coins, collectors will return the coins to the Mint. To remove the bluing on proof coins, continuous production must be stopped to polish or clean the die on a press. If the blanks are not prepared in good condition, the time to polish a pair of dies exceeds the time for stamping coins. This paper analyzes the cause of bluing on coins, reveals notable tribological principles in the coining process, and suggests methods to remove the bluing without manually polishing the die. Therefore, more efficient production of proof coins can be achieved.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
