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
Sheet metal forming simulation address a tearing problem in a metal stamping operation. A simple simulation model was created to determine the effect of blank edge radius on the height to which the material could be formed without tearing. Based on this information a new die was designed that solved the problem. There are lots of sheet metal programs available in the industry as SolidWorks and LITIO. Sheet metal forming simulation Today the metal forming industry is making increasing use of simulation to evaluate the performing of dies, processes and blanks prior to building try-out tooling. Finite element analysis (FEA) is the most common