Mint-made errors are called "type-2 blanks (or planchets)" after an upending mill adds uniform, rounded rims. Type-2 blanks may also be considered striking errors as they are prepared correctly, but are released without having been struck. A misfeed can occur when the metal strip is fed through the blanking machine. The punches sometimes overlap the leading edge of the metal producing a straight clip. Sometimes, the punches strike an area of the strip which overlaps the hole left by the previous strike producing a curved clip. Sometimes punches strike the irregular trailing edge of the metal strip producing irregular clips. Coins are
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