Eisenhower dollar R is the letter closest to it, these changes were most likely made in an effort to improve the flow of metal as the coins were struck. In 1974 and again in 1977, the Denver Mint struck a small number of pieces on silver-clad planchets, or blanks. Both times, these came from planchets which had been shipped from the San Francisco Assay Office to Denver. The first ones in 1974 were found independently by two Las Vegas blackjack dealers. The 1974 planchets were initially intended to be used for "brown Ike" proof strikings; Mint policy then was that rejected silver
Bell metal (representing Absolute and Relative Truth) is also sometimes used. A similar alloy is employed for the gongs, saron, demung, and numerous other struck metallophones of the Indonesian gamelan ensembles. In this case the tin:copper ratio is traditionally given as 3:10 by weight. Whereas bells are cast and then left to cool, the metal of Indonesian gongs and metallophones is cast as rough blanks which are then hot-forged to their final shape with hammers. Bell metal was used to cast many early Spanish, Portuguese and "Malay" cannon, most notably the Malay cannon known erroneously as "Rentaka". In Java, bell metal mixtures