COINAGE OF THE AMERICAN REGIME
1903 - 1935

Obverse and reverse of the unusual mint error 1918-S 5-centavo "Mule" (22 mm) 
struck by mistake in San Francisco, California, bearing the obverse design 
of a 20-centavo coin of the same year.
COINAGE OF THE AMERICAN REGIME (1903-1935). While the 1918 5-centavo coin was being minted in San Francisco, California, a fateful incident gave birth to what would soon become a numismatic rarity. Exactly what happened is not clear, as the mint records do not seem to reflect it.  It would appear that sometime during the production cycle, the obverse die containing the date and the shield and eagle design was inadvertently replaced with the obverse die of the 20-centavo coin of the same year. It is not known how many of these coins had been minted when the error was finally discovered and the proper obverse die put in place to complete die 2,750,000 5-centavo coins produced that year. As a result, the erroneous batch of 5-centavo coins carried on their obverse the broader shield and the smaller date originally intended for the 20-centavo 1918-S. Born that year was what is known in numismatic circles as a “MULE". A mule is a coin which carries the design intended for another coin. In the U.S.-Philippine Series,  the only other instance of mule coinage is the 20-centavo 1928-M which though not a mini error, bears the reverse design of a 5-centavo coin.

It has never been determined how many 1918-S 5-centavo mules were produced during the short time that the minting error had not been discovered and corrected. It would appear though that a very small number managed to escape the mint and went into circulation, such that almost every one that has been recovered has been found to be very badly worn. The specimen featured in this page is one (probably the best) of THREE 5-centavo 1918-S mules known to be in UNCIRCULATED condition. As such, it is EXTREMELY RARE. 

This 1918 "nickel" has been likened to the famous U.S. 1913 Liberty Head Nickel. It is certainly one of the rarest and, next only to the famous 1906-S Peso (much like the U.S. 1804 Flowing Hair Dollar), is the most famous SIGNATURE COIN of the U.S.-Philippine Series. Mintage unknown. (Philippine collection)