Mint-made errors 5 centavos. Foreign coins struck on a U.S coin planchet or vice versa are very uncommon and hold a high value. Authentic error coins should not be confused with coins that are damaged after being minted, which is known as post-mint damage (PMD) or post-strike damage (PSD). Mints purchase long strips of metal which are fed through blanking machines that punch out disks known as blank planchets (or simply as planchets or blanks) on which coins are struck. This determines the size and shape of eventual coins. The punched disks are first known as "type-1 blanks (or planchets)". The disks
Metal spinning attached. In CNC applications, carbide or tool steel cut-off tools are used. The mandrel does not incur excessive forces, as found in other metalworking processes, so it can be made from wood, plastic, or ice. For hard materials or high volume use, the mandrel is usually made of metal. Several operations can be performed in one set-up. Work pieces may have re-entrant profiles and the profile in relation to the center line virtually unrestricted. Forming parameters and part geometry can be altered quickly, at less cost than other metal forming techniques. Tooling and production costs are also comparatively low. Spin