Why it's now illegal to melt down US coins(2006)

From https://www.coinflation.com/

Name years face metal value % of face value

1909-1982 Cent (95% copper) $0.01 $0.0314770 314.77%

Jefferson Nickel 1946-2014 $0.05 $0.0813904 162.78%

Lincoln Zinc Cent 1982-2014 (97.5%) $0.01 $0.0114539 114.53%