3D Modelling and FEM Analysis on Holed Metal Coin Striking Die Mint Error

Abstract

Abstract During last decades, various mints of different countries manufactured a large amount of holed metal coin currency. As main characteristic, these holed metal coins present a central round perforation, which changes some of the initial manufacturing condition, as different coin blank or striking dies model. During the manufacturing process, these coins may encounter some error types which depend by the die dimension, the model flat area size or contour shape. Many pieces wearing these errors were minted and released; in present days these are searched and valuated by collectors. The paper work presents different aspects about the dies damages appeared at the metal holed coin striking process. In the paper beginning part, some particular introductive considerations about the holed metal coins manufactured with cracked dies error are presented; there are presented some examples. Then the simplified blank and the obverse and reverse dies 3D model are introduced, followed by the assembled model which consist in the obverse and reverse negative dies having the coin blank inside them. For these models, the finite element analysis is computed and achieved for different initial inputs. In the last part of the paper work, the analysis results and main conclusions on these are presented.